https://www.echeat.com/ INTRODUCTION Worldwide, the exponential growth in healthcare costs has led to a focus on improving the efficiency of healthcare providers. To this end, several means have been made available, such as improving the quality of leadership, which will provide effective services, improving working conditions and employees, and developing the structures and resources allocated for this purpose (Awamleh and Gardner, 1999). The laboratory is a professional bureaucracy-type organization (Mintzberg: 1989) with multiple and heterogeneous components, with a diversity of profiles of the different actors who rub shoulders daily. A good manager, who wants to succeed in a competitive environment, must consider this hetero-complexity, in this particular institution "where neither error nor delay are tolerated, due to a vital prognosis that can be engaged at any time" (N. EBOLO: 2019). Beyond the action of the Ministry and the various health administrations, a large part of what we have to invent comes back to the actors in the field. In this scheme, managers lead in supporting change and adapting organizations to new challenges. It is they, through their ability to understand the needs of the populations, their proximity to the professionals working in the various professions, and their in-depth knowledge of the realities of the communities, who are and will be able to define and implement the most effective organizational modalities to meet the challenges of the health system (Ham, 2012; Storey and Holti, 2013). To evaluate these different parameters, we will therefore show, firstly, the importance of the organizational structure and the type of management in improving the quality and reducing variations in health services is one of the most important objectives of governments and societies as a whole; second, to present the impact of different leadership styles on health care outcomes and the validation of leadership theories in the health care context. Third, we will respond to debates about the nature and effectiveness of the implementation of the National Health System (NHS) improvement programs: the Knowledge Skill Framework and the Agenda for Change. I. IMPACT OF HIERARCHY WITHIN THE NHS The hierarchical line is made up of the management of the organization. Indeed, it is the company's executives who serve as a transmission belt between the strategic top and the operational center. She embodies the voice of the strategic top and aims to spread her message to the teams at the bottom of the hierarchical pyramid. For example, in the area of care 2024-11-01T04:12:38.537-04:00 http://75.150.148.189/free-essay/Improving-the-efficiency-of-healthcare-providers-45591.aspx The Bicep The long head of the biceps (LHB) brachii tendon originates at the supraglenoid tubercle and superior glenoid labrum. Its labral origin is mostly posterior in over half of cases, and the tendon, on average, is 9 cm in length. Inside the joint, the tendon is extrasynovial and passes obliquely, heading toward the bicipital groove. As it exits the distal bicipital groove in the upper arm, the long head of the biceps tendon joins the short head of the biceps tendon (SHBT) as both transition into their respective muscle bellies in the central third of the upper arm. After crossing the volar aspect of the elbow, the biceps brachii inserts on the radial tuberosity and medial forearm fascia. The latter occurs via the bicipital aponeurosis.[6] The distal insertion point has become a relevant yet a controversial topic of interest. Over the last decade, there has been a renewed interest in investigating the insertional anatomy of the distal biceps tendon, specifically concerning its relevance in the evolution of distal biceps reconstruction techniques. Historically, the insertion site was described as one homogenous tendon that inserts on the radial tuberosity. More recent studies have reported its distal attachment as two distinct tendons. More specifically, recent studies have demonstrated the presence of an entirely bifurcated distal biceps tendon insertion. The studies found that the short head of the distal biceps tendon commonly inserts more distally than the long head and typically inserts at the apex of the tuberosity. The long head passes deep to the distal tendon of the short head before inserting proximal to the tendinous footprint of the short head.[7] ’’ ‘’’’’’’’’’’’’’’’’’’’ Biomechanics The biceps brachii muscle primarily is a strong forearm supinator but a weak elbow flexor.[8] Biomechanically, the long head of the biceps tendon has a controversial role in the dynamic stability of the shoulder joint. It has been demonstrated, mostly in biomechanical cadaveric-based studies and animal models, that the tendon at least plays a passive stabilizing role in the shoulder. Neer proposed in the 1970s that the long head of the biceps tendon's stabilizing role varied depending on the position of the elbow. Several subsequent studies refuted the theory that the long head of the biceps tendon played an active shoulder stabilizing effect.[9] Jobe and Perry evaluated the activation of the biceps during the throwing motion in athletes. The authors reported the peak muscle stimulation occurred in relation to elbow flexion and 2023-12-26T11:51:17.273-05:00 http://75.150.148.189/free-essay/The-Bicep-45584.aspx Prokaryotes vs. Eukaryotes There are lots of different and interesting types of living things on our planet. I think you already knew that though. You’ve probably seen an abundance of unique organisms like giraffes, mushrooms, worms, alligators, grasshoppers, bacteria, algae, and apple trees. Did you know that all of these very different organisms are divided into two categories? That’s right – every living thing on the planet can be classified into two groups based on the cells that make them up. So let’s talk about these cells. I hope that you already knew that cells are the basic units of life, and that all living things are composed of cells. Although all cells have some things in common, each cell type also has unique characteristics that make them easy to identify. Let’s focus on these unique characteristics. Prokaryotes Our first cell type is called a prokaryotic cell or prokaryote (pro-kar-e-oat). These cells are unique because they are only found in the smallest organisms on the planet, bacteria. Scientists believe that these bacterial cells (prokaryotes) were the very first life forms on Earth. That means that these cells have been on the planet longer than any other living thing. Bacteria are really old! So what makes bacterial cells different from all other types of cells? These prokaryotic cells are very simple and small. It’s their simplicity that makes them so easy to recognize. Prokaryotes do not have any membrane-bound organelles (cell parts). That means that bacteria don’t have a nucleus (PRO-NO). That’s crazy! Their DNA just floats around. So what does this all mean? Prokaryotes are the simplest of all cell types: they are very small, unicellular (made of one cell), and they do not have a nucleus. Eukaryotes If bacteria are the only living examples of prokaryotes, everything else on the planet must be composed of eukaryotic cells. Eukaryotes (U-kar-e-oats) are much bigger than prokaryotic cells. Some eukaryotic cells are even large enough to be seen without a microscope! Eukaryotic cells are complex. They have lots of different rooms or compartments inside of them. These rooms are called membrane-bound organelles. Some examples of these rooms are mitochondria and endoplasmic reticulum. The most important organelle in a eukaryotic cell is its nucleus. This is the control center 2021-12-15T10:49:58.36-05:00 http://75.150.148.189/free-essay/Exploring-Cell-Types-45532.aspx Did you know the effects of climate changes include rising sea levels, regional changes in precipitation, more frequent extreme weather events such as heatwaves, and expansion of deserts? Ocean acidification is also caused by greenhouse gas emissions and is commonly grouped with these effects even though it is not driven by temperature. Surface temperature increases are greatest in the Arctic, which has contributed to the retreat of glaciers, permafrost, and sea ice. Overall higher temperatures bring more rain and snowfall, but for some regions droughts and wildfire increase instead. Climate change threatens to diminish crop yields, harming food security, and rising sea levels may flood coastal infrastructure and face the abandonment of many coastal cities. Fortunately, there are always things that we can do to fight against these terrible changes. Saving the environment starts with us and it is our responsibility to act against these terrible changes to preserve the planet for future generations. Recycle According to King county.gov, Page one. “ recycling helps reduce greenhouse gas emissions by reducing energy consumption.” Manufacturing plants emit a large number of greenhouse gasses per year. It is unavailable in the production of goods that we use on a regular basis. However, a cleaner alternative would be to invest in recycling. Recycling is a cost-effective and eco-friendly process that eliminates waste and doesn’t emit greenhouse gasses into the environment. Be sure to collect your discarded paper, glass, plastic, and electronics at your local recycling center the professionals will take these items to a processing plant where there will be remade into other recyclable materials again. Be More Conservative with Energy Usage According to science direct.com, on page one. “ energy conservation has often been referred as to the fifth fuel, the other for being the so-called primary or fossil fuels of wall solid oil liquid, gas, and nuclear hydroelectricity.” Becoming more energy efficient is a great way to prevent pollution. It causes the power plant to expend less energy that can lead to the production of greenhouse gasses. This means that you should do what you can to cut down on energy usage in households. Make sure to turn off lights and unplug devices that you are not using anymore when you are done with them. Replace light bulbs with energy-efficient light bulbs to help you save electricity. Make Your Commute Green According to Lettie Stratton, how to do it and why it's important, page1. “ green commuting can 2021-11-16T16:16:32.58-05:00 http://75.150.148.189/free-essay/EFFECTS-OF-CLIMATE-CHANGE-AND-WAYS-TO-HELP-PREVENT-IT-45517.aspx Stem Cell Research Name: Institutional Affiliation: Tutor: Date: Stem Cell Research Stem research is a significant stride in the field of biomedicine. Through this field, scientists have been able to find out various developments that have taken place. The research entails the study of molecule antimicrobials and the modern genetics. Besides, there has been the study of cell therapy and genomics. Stem cells are immature cells that keep dividing to produce more and more cells. The cells produce stem cells, or they can transform into specialized cells such as heart, liver, skin or brain cells. The paper is going to discuss the various types of stem cells, the science, and ethics behind them. Stem cells are of different types. For example, the embryonic, adult and iPS stem cells. The embryonic stem cell is said to be found in the embryos, and it matures to become a specialized type of cell in the body. These cells can be obtained from a variety of sources. These sources include embryonic stem cell lines, those embryos that are generated from the nuclear genome transfer and finally, these cells can be gotten from unused in vitro fertilization procedures. Besides, adult stem cells are obtained from the bone marrow. The adult stem cells are usually obtained after birth. Study shows that these adult cells have the ability to develop into various types of cells. To sum up, the IPS cells are the type of cells that are in most cases produced in the laboratories. These cells play various roles in body development and growth (Austin, 2012). Also, research that has been conducted based on the stem cells has shown that these cells have two crucial features (Campo-Ruiz, 2012). The first characteristic is that these cells have the ability to renew themselves. The renewal process takes place through the cell division. Another significant feature of the stem cells is that they have capacity to become tissue cells. The feature is usually achieved under some specific controlled experimental conditions. When these cells have been modified, they perform specific functions in the body. Besides, scientific investigations have shown that cell division takes place in some specific parts of the body such as the gut. Biologically, it is evident that stem cells grow into the different type of cells in the body that are modified to perform various functions. Two or more of these cells are combined to make a body tissue. The tissue in the body performs 2016-12-14T03:06:07.5-05:00 http://75.150.148.189/free-essay/Stem-Cell-Research-35258.aspx Essay Questions Name: Institution: Essay Questions Q1. The process of oxidative phosphorylation takes place in the mitochondria. Electrons are moved from FADH2 or NADH to O2 to form ATP. It involves proton-motive force generation during electron transport. On the other hand, electron transport chain (ETC) is the series of organic molecules and proteins in the inner mitochondria membrane. Electrons moves through the members of the transport chain in a series of redox reactions (Murray, Rosenthal, and Pfaller, 2015). As a result, they release energy, which is captured as proton gradient to make ATP through chemiosmosis process. The high energy levels of NADH electrons make it a good electrons donor in a redox reaction. Therefore, it can directly transfer electrons to complex I. Contrary, the low energy levels of FADH2 makes it a poor electron donor; hence, it cannot move them to complex I. Q2. Glycolysis is the first stages of bacterial respiration that happens in a clear cytoplasm portion called cytosol. It involves splitting of glucose molecule into pyruvic acid, a two- 3carbon molecule. Next is the Krebs cycle where the Acetyl-Coenzyme A (CoA) breaks down into protons and carbon dioxide. It then releases energy in the form of electrons, which are used by NAD+ to form NADH. The last stage happens in the interior membrane of mitochondria. It involves the transfer of NADH from one protein to another. Respiration does not require oxygen, it produces water molecules, glycolysis occurs in the cytoplasm, and it has a net gain of 32 ATPs. Conversely, fermentation requires oxygen, it does not produce water molecules, all reactions take place in the cytoplasm, and it has a net gain 2 ATPs. Q3. Carbon- constituent of cellular material Oxygen- constituent of cell water and material Nitrogen- constituent of nucleic acids, amino acids, and coenzymes Hydrogen- constituent of cell water and organic compound Phosphorous – constituent of phospholipids, nucleic acids nucleotides, and teichoic acids Defined medium is a nutrient material with a known exact chemical composition while the complex medium is a nutrient material with unknown exact chemical composition. Q4. Functional media types are used in cell culture to facilitate microorganisms’ growth. They include differential, selective, and enriched media. Transport media is used prevent overgrowth of contaminated commensals and organisms. Examples include alkaline peptone water and Cary-Blair medium. Selective media is used to encourage and suppress the growth of desired microbes and unwanted bacteria respectively. For example, brilliant green agar, campylobacter agar, and EMB 2016-12-10T13:22:50.957-05:00 http://75.150.148.189/free-essay/Essay-Questions-Biology-35256.aspx We all love pets. But is it worth to keep wild animals at home and use them as pets? How will they feel? What will they do? How would they react to this? Now I will try to tell you about it. On the one hand, it sounds exciting. If you care for animals, it is possible that will save rare species from extinction. Also, if you find a small, wounded, abandoned animal, help it. The animal will be linked with you and will be your pet. In addition, it is very interesting to watch it; you can examine your pet from all sides. On the other hand, it may result in poor consequences. The beast cannot fall in love with you and become dangerous for you. Not everyone knows how to deal with wild animals, and it can lead to danger for the pet as well 2015-05-02T02:38:57.807-04:00 http://75.150.148.189/free-essay/Keeping-wild-animals-as-pets-35106.aspx Photosynthesis and Cellular Respiration Estee 2014-11-05T00:02:46.237-05:00 http://75.150.148.189/free-essay/photosynthesis-respiration-35062.aspx Necrotizing fasciitis, commonly known as flesh-eating disease or flesh-eating bacteria syndrome, is a rare infection of the deeper layers of skin and subcutaneous tissues, easily spreading across the fascial plane within the subcutaneous tissue. The most consistent feature of Necrotizing Fasciitis was first described in 1952 by Wilson, as necrosis of the subcutaneous tissue and fascia with relative sparing of the underlying muscle. Necrotizing fasciitis progresses quickly, having greater risk of developing in the immunocompromised due to conditions such as diabetes or cancer. It is a severe disease of sudden onset and is usually treated immediately with surgical debridement and high doses of intravenous antibiotics, with delay in surgical treatment being associated with higher mortality. Many types of bacteria can cause necrotizing fasciitis (e.g., Group A streptococcus (Streptococcus pyogenes), Staphylococcus aureus, Clostridium perfringens, Bacteroides fragilis, Aeromonas hydrophila). The disease is classified as Type I (polymicrobial, due to a number of different organisms) or Type II (monomicrobial, due to a single infecting organism).The majority of cases of necrotizing fasciitis are polymicrobial, with only 15% of cases being Type II Such infections are more likely to occur in people with compromised immune systems secondary to chronic disease. Historically, most cases of Type II infections have been due to group A streptococcus and staphylococcal species. However, since as early as 2001, another serious form of monomicrobial necrotizing fasciitis has been observed with increasing frequency, caused by methicillin-resistant Staphylococcus aureus (MRSA). Signs and symptoms Over 70% of cases are recorded in patients with at least one of the following clinical situations: immunosuppression, diabetes, alcoholism/drug abuse/smoking, malignancies, and chronic systemic diseases. For reasons that are unclear, it occasionally occurs in people with an apparently normal general condition. The infection begins locally at a site of trauma, which may be severe (such as the result of surgery), minor, or even non-apparent. Patients usually complain of intense pain that may seem excessive given the external appearance of the skin. Patients initially present with signs of inflammation, pyrexia and tachycardia. With progression of the disease, often within hours, tissue becomes progressively swollen, the skin becomes discolored and develops blisters. Crepitus may be present and there may be discharge of fluid, said to resemble "dish-water". Diarrhea and vomiting are also common symptoms. In the early stages, signs of inflammation may not be apparent if the bacteria are deep within the tissue. If they are not deep, signs of inflammation, such as redness and swollen or hot 2013-10-25T05:16:32.72-04:00 http://75.150.148.189/free-essay/Flesh-Eating-Bacteria-34977.aspx 2013-09-22T08:52:58.33-04:00 http://75.150.148.189/free-essay/Save-the-Environment-34968.aspx HEALTHY LIFE STYLE AND COLORECTAL CANCER Life style resembles on our health. When we practice good pattern of living; it would ensure the vitality of our well being. Good pattern of living is equivalent to the healthy lifestyle. What is meant by healthy lifestyle? Healthy life style is one of the best defenses against various health-related problems. This type of life style includes healthy diet and regular exercise plan. At the same time, it also imposes life style which is not addicted to smoking and alcohol. When we talk about having a healthy diet and exercise, how many of us are practicing on this? In this era of globalization and drastic economical growth. Most of us are busy concentrating on ways to improve our financial standard rather than having healthy food. As the fast food branching out, we prefer to have food at fast food centers. After tiring day at work fast food centers has become the choice of food for many. Fast food does not contain a complete diet. Too much of fast food and irregular diet plan creates problem to health. World wide variously affecting diseases which are obesity. Obesity-in normal term is overweight but scientifically it is defined as a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health. Obesity imposes a greater risk of developing colon cancer for men of all ages and premenopausal women than it does in postmenopausal women. It been proofed scientifically that obesity is one of the cause of colorectal cancer. Insulin is one of the biochemical mediators between obesity and colorectal cancer. The visceral abdominal fact has been identified as the essential fat depot for pathogenetic theories that relates obesity and colorectal cancer. Consumption of alcohol and smoking also one of the causative lifestyle which promotes colorectal cancer. Alcohol and the smoke contain tobacco damages body tissues. In our colon and rectum, bacteria convert alcohol into large amount of acetaldehyde. Acetaldehyde is a cancer causing chemical. These damaged cells may try to repair themselves, this triggers DNA changes in cells. Changes of DNA cells results in multiple growth of cells at the spot of cell repair happens. Multiple growth and the accumulated cells leads to the cancerous cells which later leads to colorectal cancer. Alcohol and cigarette lowers the folate intake of body. Heavy consumption of alcohol and smoking habit 2013-05-10T01:58:13.097-04:00 http://75.150.148.189/free-essay/HEALTHY-LIFE-STYLE-AND-COLORECTAL-CANCER-34882.aspx Smell Consider any aspect of the human sense of smell and choose any genre (but you can not choose a narrative or argumentative) in which to compose a reflection on the human sense of smell. Goals I intend to write a comprehensive paper on the aspects of the human sense of smell. Identifying and understanding the process of smelling Identifying the physiological parts involved in smelling. Animals have five different senses that enable them to function. The sense include, smelling, hearing, seeing, feeling and tasting. All the five senses are important in the manner in which they are of use to animals. Each of the five different senses has a different organ through which it utilizes to carry out its function. Smelling is carried out through the anatomical part known as the nose. In humans, the nose appears as a protrusion form the face (the size varies among different individuals). Some animals such as dogs have a stronger sense of smell in comparison to other animals such as humans. The nose has features that ensure its smelling function is effectively executed. The nose cleans, warms and moistens air before it is transported to other breathing organs such as the lungs. Transport of fresh air that contains oxygen is very important and important for life to be sustained (Alters 93). If foul and toxic gases are smelled and breathed into the human body, they might lead to collapse of normal body processes.The sense of smell organ; nose, closely works in close conjunction with other body organs such as the eyes. However, even individuals without the sense of seeing also have effective senses of smelling. In the past, it was thought that blind individuals have better senses for smelling. However, recent studies indicate that they have similar smelling capabilities as individuals with normal eyesight. Smells that are produced by different substances have different vapors which they produce, generate and it is then detected by the receptors in the nose. The nose has membranes that are lined with receptors which are linked to the olfactory nerve. The nose has small hairs that filter the air that is breathed in before it is inhaled to other body parts such as the lungs. The airs ensure that no physical obstructions enter through the nose. The lungs need the air that is inhaled to be as clear as possible. After the air moves through the nose, it 2013-04-17T03:32:34.6-04:00 http://75.150.148.189/free-essay/Write-any-essay-about-smelll-34860.aspx Karenia brevis usually reproduce by asexual process, dividing into two cells, then into four and so on. Firstly, cysts of the karenia brevis lay on the ocean floor and might stay in the ground for years, without being disturbed. Oxygen and other conditions, such as the right temperature and pressure are essential for the beginning of the germination process. When the temperature increases, as well as the light absorbsion, the cyst breaks open and a swimming cell appears to the ocean. After a few days time the cell reproduces by simple division and as a result hundred of cells will reproduced within weeks, having the same number of chromosomes in the nucleus. However, is really important to mention that karenia brevis might have sexual reproduction and a new life change and that happens only when the organism cannot have access in available nutrients, thus growth stops and gametes are formed. During gametogenesis the chromosomes in the nucleous reassume a typical dinokaryotic appearance, the nuclear envelope appears in all mitotic stages and the mitotic spindle is extracellular. Spindle microtubules pass through furrows and tunnels that form in the nucleus at prophase (Dodge 1987). Some microtubules contact the nuclear envelope, lining the tunnels at points where the chromosomes also contact. The chromosomes usually have differentiated, dense regions inserted into the envelope. After that, the two cells (gametes) join together. Syngamy involves equal motile gametes and is called isogamy. Then, the formed cell develops into a zygote by homothallism, which is the gamete fusion in clonal strains. The product of gamete fusion is a planozygote, which may remain motile for hours or a few days. Eventually a non-motile thick-walled resting cyst (hypnozygote) is formed. Excystment occurs after a varying length of time of inactiveness. Meiosis is heralded by a peculiar churning and rotation of the nucleus, a process called nuclear cyclosis associated with the pairing of homologous chromosomes .Meiosis may occur before or after the encystment and is normally accomplished in two successive divisions. The mobile zygotes follow the long-term encystment (resting cysts). The inactive cysts fall into the bottom of the ocean until the time is appropriate for another germination (Mona Hoppenrath and Juan F. Saltarriaga, 2008). Many scientists have done research about the life cycle of Karenia brevis in order to find out if is connected with the main effects of red tides in humans and animals. Karen 2013-04-04T06:43:16.96-04:00 http://75.150.148.189/free-essay/Karenia-Brevis-34847.aspx Cell membrane A cell membrane is the outer surrounding of the cell that controls what goes in and out. Also cells need to have a dynamic equilibrium amongst other molecules. There are two types of cellular diffusion; Simple Diffusion and Facilitated Diffusion. Osmosis is also another type of diffusion that involves the transfer of water in the organism. None of the diffusions require energy because it is a natural process that transfers the areas of high concentration too low. Active Transport on the other hand does require energy because the movement of the molecules in the opposite direction of the diffusion, even when the equilibrium is reached the cell still needs the molecules around it. Endocytosis and Exocytosis are both very important to the cells. When a cell membrane takes in molecules it is called Endocytosis. Endocytosis is a process by which the particles are taken in by the cell, from the outside to the cytoplasm inside a vessel. Exocytosis is a process by which the particles of waste are taken out of the sell. Then the vesicles travel to the Golgi apparatus. By Endocytosis the energy is transferred through the cytoplasm of the cell. Sometimes the cell has a lower level of proteins than its surroundings. That is called diffusion. Diffusion occurs when the surrounding of the cell has fewer molecules than the inside of it. Then the cell uses diffusions to transfer the molecules into the cell. When diffusions are complete the outcome is called the dynamic equilibrium. Osmosis occurs often too, only with water particles in the organism. Osmosis is used also to establish equilibrium. Sometimes if a membrane can only pass water particles, so the water will adjust itself to have the same hypertonic solution. There are more types of ways diffusion is used with energy. Facilitated diffusion and active transport are almost the same things, but then the facilitated diffusion tries to adjust the dynamic equilibrium. For example when the protein carrier takes the same amount of molecules, it requires no energy. The active transport uses energy to take more of the molecules that the cell needs, therefore making the numbers of molecules on the outer side fewer than inside the cell. For example, red blood cells use the facilitated diffusion to move glucose across membranes. Some sugars and amino acids are used in the active transport. The thing called Selective permeability also occurs in 2012-12-02T10:43:38.38-05:00 http://75.150.148.189/free-essay/The-Cell-Membrane-34757.aspx My current fitness and nutritional habits are consistent with those of many middle- aged men. Presently am about 15 pounds over my ideal weight. My weight has remained consistent for the last 20 years. My regular diet includes a variety of proteins, including red meats, chicken, and fish. I eat vegetables on a semi-regular basis. However, I do not eat enough fruits, nuts, and legumes. I drink coffee black on a daily. I do not drink carbonated soda. I seldom eat fast foods. I only use olive, and canola oil at home. For the last five years, I power walk four to five times a week during the summer. Other than my summer walking routine, I live a sedentary lifestyle. As a result, and have developed unhealthy belly fat. Obesity has become a growing epidemic in America. “On average, U.S. adults weigh 24 pounds more than they did in 1960 (5), and they are at increased risk for health conditions such as diabetes, cardiovascular disease, and certain cancers Studies have shown a link between obesity and high blood pressure, diabetes, and cardiovascular disease” (CDC, 201, p.42). These statistics affect African Americans at a higher rate. Eighty percent of Black women aged 40 years or older are overweight or obese (Donettelle, 2010, p.282). These numbers are projected to grow worse as American become fatter. I believe that by incorporating three new fitness habits into my lifestyle I can improve my present health. • My first objective is a year round aerobic program that combines power walking and swimming. This would allow me to power walk during the spring and summer, and swim during the colder fall and winter months. This will eliminate six sedentary months. • My second goal is to improve my flexibility by adding yoga as a fitness habit. Yoga incorporates breathing and an array of static stretching exercises expressed as Postures (Donattelle, 2010, p.331). As we grow older, our ability to maintain flexibility with the aid of yoga adds to our health and quality of life. • My third goal is to increase my core strength by adding a strength-training program. I do not need a fitness club to do this. A light to moderate fixed weight training routine only needs several dumbbells. This added 2012-09-26T20:47:18.543-04:00 http://75.150.148.189/free-essay/Nutrition-and-Fitness-Paper-34649.aspx AbstractAn F1 progeny derived from a cross between the apple (Malus x domestica) cultivars Telamon and Braeburn was used to identify quantitative trait loci (QTL) linked to the vitamin C (l-ascorbate [l-AA]) contents of fruit skin and flesh (cortex) tissues. We identified up to three highly significant QTLs for both the mean l-AA and the mean total l-AA contents of fruit flesh on both parental genetic linkage maps, confirming the quantitative nature of these traits. These QTLs account for up to a maximum of 60% of the total population variation observed in the progeny, and with a maximal individual contribution of 31% per QTL. QTLs common to both parents were identified on linkage groups (LGs) 6, 10, and 11 of the Malus reference map, while each parent also had additional unique QTLs on other LGs. Interestingly, one strong QTL on LG-17 of the Telamon linkage map colocalized with a highly significant QTL associated with flesh browning, and a minor QTL for dehydroascorbate content, supporting earlier work that links fruit l-AA contents with the susceptibility of hardfruit to postharvest browning. We also found significant minor QTLs for skin l-AA and total l-AA (l-AA + dehydroascorbate) contents in Telamon. Currently, little is known about the genetic determinants underlying tissue l-AA homeostasis, but the presence of major, highly significant QTL in both these apple genotypes under field conditions suggests the existence of common control mechanisms, allelic heterozygosity, and helps outline strategies and the potential for the molecular breeding of these traits. Vitamin C (l-ascorbic acid [l-AA]) is essential for all living plant tissues. Apart from well-known functions in oxidative stress defense, associated with its antioxidant properties and its abilities to detoxify reactive oxygen species, it also has important roles in the regulation of plant cell growth and expansion, photosynthesis, as well as hormone functions (for review, see Davey et al., 2000; Smirnoff, 2000). Even though nutritional deficiencies are rare in modern western cultures, it is generally recognized that dietary l-AA also has important health benefits for the consumer, and an increased intake of vitamin C has been associated with a decreased incidence of several important human diseases and disorders (Carr and Frei, 1999; Demmig-Adams and Adams, 2002; Hancock and Viola, 2005). Furthermore, in meat-poor diets, dietary l-AA can contribute to the improved uptake of iron and zinc, which are the major micronutrient deficiencies worldwide (Frossard et al., 2000). In apple (Malus x domestica) and 2012-06-20T19:50:00.28-04:00 http://75.150.148.189/free-essay/Genetic-Control-of-Fruit-Vitamin-C-Contents-34594.aspx A friend in need is in deed. Plants and animals are our best friends as they fulfill all our needs. Without them our life would be unthinkable. All our food comes directly or indirectly from plants in form of fruits, vegetables, pulses, rice, wheat 2012-04-20T05:28:51.32-04:00 http://75.150.148.189/free-essay/Plants-and-Animals-are-our-friends-34543.aspx Research Essay: The Brain In the 1800s through the 1900s the central theory is that the unconscious mind drives much of human behaviour even though civilised society stresses the importance of overriding primitive impulses with morality and reason. Yet this constant tension between a person’s repressed drives and his expected social actions often causes psychological distress. Freud suggests that one of the ways this tension is resolved is through the fantasy world of dreams. An important distinction between the manifest and latent content of dreams. In his view, the manifest content is the remembered elements of the dream or its apparent narrative. The latent content is the underlying thoughts and wishes the dream represents. Freud argues that this latent content of dreams is based on fantasies related to the emotional experiences of childhood. Through psychoanalysis or “dreamwork,” patients are able to uncover the unconscious wishes or motives that lie behind a particular dream and so gain a greater understanding of themselves. In 1929 Hans Berger develops the first electroencephalograph, an instrument for recording the electrical activity in the brain. Commonly known as the EEG or brainwave test, Berger’s invention is now routinely used as a diagnostic test in neurology, psychiatry and brain research. Present studies agree that the brain is highly specific and divided. Some areas handle speech, others visual, others touch, and much more. Most of the brain works automatically outside of the ability of the individual to control the process of cognition. Research has shown that the brain has grown larger from the tiny reptile brain by overlaying each previous brain set with a new brain capable of new abilities. This is done much like building a house. You may start out with a one room house. As you add on, the one room is not stretched and made larger, more rooms are added and each new room has a specific function such as kitchen, bedroom, playroom, den, etc. Scientists have identified eight such layers, each containing specific capabilities and characteristics. The capability of each brain segment has been mapped and identified. In the present neurobiologists are working on how perception, cognition, and memory are coded and stored within the brain. Recent studies are based on simultaneous monitoring of the activity of hundreds of associated, localized neurons. The functional properties of these groups of neurons have been identified. These studies seem to indicate the theory of distributed coding is the 2012-03-23T11:48:20.017-04:00 http://75.150.148.189/free-essay/The-Brain-34522.aspx This essay examines the changes throughout the life cycle of flowers, frogs and butterflies. I Introduction These papers overall consider the themes of pregnancy and the changes in a woman’s body, and the metamorphosis of living things. Pregnancy, in one sense, is such a metamorphosis: the woman’s body is the cocoon from which new life emerges. Let’s explore the changes in insects, frogs and flowers as examples of metamorphoses in nature. II Discussion Metamorphoses in nature are amazing: caterpillars become butterflies; tadpoles become frogs; and seeds become flowers. These changes are amazing, for they involve not only rapid growth, but complete transformations from one physical form to another. When trying to describe the cycles of nature, there’s no real way to determine a starting point. But since it seems logical, we’ll look at the butterfly’s life cycle as beginning with the egg. The eggs are laid by the female on the appropriate plant, in and about five days a tiny wormlike caterpillar hatches. The caterpillar immediately begins eating the plant food on which it has hatched; it also sheds its skin, usually four times, a process called ecdysis, The caterpillar at this point is transformed into a creature called a pupa, which spins a cocoon for the final transformation. The cocoon may seem lifeless, but inside the caterpillar is in the process of becoming a butterfly. The caterpillar literally liquefies and is reassembled into one of the most gorgeous creatures in nature. The four stages are quite distinct: egg, caterpillar, pupa, butterfly. In each, the insect eats different foods and has a distinctly different appearance. (“The Amazing Life Cycle of the Butterfly,” PG). This process is entirely dissimilar from that of mammals, where one knows a kitten will become a cat; a puppy a dog; and a baby a human. Here, there is no corresponding physical resemblance between the developmental stages. The same type of oddly dissimilar physical stages occurs in the development of frogs. Frogs are amphibians, a class of animal that spends part of its time in the water and part on land. Like butterflies, frogs lay eggs, only the female lays the in the water. When they hatch, the tiny creatures are known as tadpoles, and they breathe through gills as fish do. As the tadpoles mature, they grow legs, and begin to develop lungs 2011-10-31T00:50:25.427-04:00 http://75.150.148.189/free-essay/Metamorphosis-Metamorphoses-in-Nature-34244.aspx The possibilities are endless it seems. Today’s scientific knowledge and technology is ever advancing and increasing. Science and technology has become a bigger part of our everyday lives today than most people might realize. With magazines like “Popular Science” or “Scientific American” being published every month packed full of the latest cutting edge technology and scientific discoveries, it’s easy to see that the realm of science and technology is a major factor in the modern world we live in. However, the field of science today has morphed to some degree from what it was like say, three hundred years ago when Isaac Newton explained the basics of motion. Today, science is less a means by which we gain an understanding and appreciation of the world around us, as it is an application of that knowledge to utilize and employ the world around us for our benefit. These applications, we call technology. Science has made the impossible possible, and technology has allowed things to be done that no one had ever dreamed could be done. It’s about pushing the limits. That leads us to ask the obvious question, when should the limits no longer be pushed? Simply because we can do something, does that mean we should? By asking these questions, a whole other domain is opened up called ethics. A discussion of ethics and ethical behavior will often quickly find its way to a discussion about the relationship between religion and ethics. Science, ethics, and religion are an interesting combination but an important and relevant one today. Biotechnology, the fusion of biology and technology, is a field that often falls under criticism from ethical and religious points of view. Most notably, debates of the ethical or unethical nature of abortion, cloning, and stem cell research have arisen. In order to form a knowledgeable and well-informed conclusion about the ethics of modern biotechnology, it is necessary to study the extent of interplay between these three factors in today’s modern biotechnology and what their relationship has been historically. First of all, a clear definition of the three terms at hand may shed some helpful light and provide a solid foundation. By definition, ethics is an attempt at creating a system of morals that define our perception of right and wrong. Ethics becomes 2009-01-25T04:13:09-05:00 http://75.150.148.189/free-essay/Science-Ethics-and-Religion-33947.aspx Meiosis is a two-part cell division process in organisms that sexually reproduce. Meiosis produces gametes with 2008-11-19T21:00:06-05:00 http://75.150.148.189/free-essay/A-basic-overview-of-meiosis-production-of-sex-cells-33882.aspx Stem Cell Research: Pro’s, Con’s and development over the years Process Paper For National History Day, we chose our topic of Stem Cell Research for many reasons; it is a highly controversial topic, a very close to heart topic, a very interesting topic and it has lots of conflicts, each with a compromise. Our topic is highly controversial because of all the different aspects of the research itself and all the ways they are being viewed. For example, the moral battle over stem cell research is the most common debate. Many people believe that because a human embryo, a living, unborn child, is being destroyed in the process of isolating stem cells, that the research is wrong. However, many others believe that because the research could save lives and help devastated families, it would be unethical to merely dispose of them. Conducting our research was a fairly simple undertaking; five resources were used: Internet, interviews, classroom texts, newspaper articles and books. For the internet, we were able to find websites pertaining to stem cell research history and we used fertility clinic web pages to look at what current research was being conducted with private funding. We were also lucky enough to contact Richard Galli, author of Rescuing Jeffrey, a memoir about his son’s dive into paraplegia, and acquire a chance to interview them both. Additionally, we interviewed a biology teacher at our school to learn more about what stem cells are. Also attained from a biology class were texts explaining what stem cells are and where they were first isolated. Newspaper articles also gave us information as far as history because articles from many years ago about, then, current breakthroughs, could be read, giving us a firsthand look at what America saw at those times. Our presentation type is a documentary and we chose this for many reasons; firstly, resources to make a documentary (film equipment, editing software) are easy to access and work with- even digital cameras are able to record videos as well as take useful pictures. Secondly, we both have prior knowledge on how to use these resources- computers come with programs that give users the opportunity to create and edit their own videos. Thirdly, a documentary is the best fitting way to display our information; a documentary shows many pictures which is a good milieu for substantial dialogue. Lastly, a documentary gave us the ability to show 2008-09-04T23:45:56-04:00 http://75.150.148.189/free-essay/Stem-Cell-Research-Pros-Cons-and-Developements-Over-the-Years-33691.aspx Mitosis Root tip microscope lab Biology PROBLEM: What are the phases of mitosis in a root tip? HYPOTHESIS: Using a prepared onion root slide and a microscope, can you identify, label and count cells undergoing mitosis? METERIALS: -Microscope -prepared slide of an onion root tip PROCEDURE: 1. set up a compound light microscope and turn it ob 2. place a slide containing an onion root tip under the microscope 3. locate the growth zone, which is right above the root at the root tip 4. focus on low power and then switch to medium or high power, use the pictures of the stages of mitosis to identify the stages on the microscope slide 5. count the number of cells 2008-09-04T23:35:09-04:00 http://75.150.148.189/free-essay/Mitosis-Root-Tip-Microscope-Lab-Paper-33680.aspx Genetic disorders: Bipolar Disorder Sunday, March 23, 2008 Research paper Bipolar disorder, also known as manic depression disorder, is a serious two-faced mental illness that affects approximately two million people all across America today. Bipolar is characterized by a cycle of mood swings between elation (mania) and extreme depression. (www.managingbipolar.com) Mania is the euphoric phase that is characterized by an exhilarated or irritable mood that generally lasts at least one week. A manic episode is represented by change from normal feelings to having feelings that often interfere with work, school and personal relationships. Usually, Mania is the first episode in males. Some people experiencing a manic episode require hospitalization to return to a normal level of functioning, others require anti psychotic medications such as Quetiapine, Olanzapine or chlorpromazine. Symptoms of Mania include: excessive talking/pressured speech, an inflated self-esteem, decreased need for sleep, distractibility, irritability and excessive involvement in activities with pleasurable activities or high potential for destructive consequences. (www.mayoclinic.com) When people in a manic state experience the symptom of racing thoughts or ideas, they feel like they are tuned into two or three sets of televisions on at once which may cause a person to switch a topic from on conversation to another or become greatly confused and agitated. When a manic person has inflated self-esteem, they feel as though they could do things that they, normally, would never be able to accomplish, such as winning the Olympic gold medal or become the President of the United States of America or more simply, fly when jumping out of a building. The decreased need for sleep is the most common symptom of the manic period. A person experiencing mania may only get a few hours of sleep every night or not get sleep at all and claim to feel refreshed and energized. There are three stages of mania that starts with hypomania. During the hypomania stage, the bipolar patients say that they are energetic, and assertive. The hypomania state seems as though the patients are addicted to their mania. The second stage to mania is shown by a loss of judgment and an irritable mood. The third stage is evident when the patient experiences delusions and behavior becomes hyperactive. The other phase of Bipolar Disorder is the depressive phase. A depressive episode is characterized by a depressed mood or a loss of interest 2008-09-04T23:34:24-04:00 http://75.150.148.189/free-essay/Genetic-Disorders-Research-Paper-on-Bipolar-disorder-33679.aspx Biosensors are analytical devices used to measure biological information that converts a bodily response into an electrical signal. Biosensors consist of three major parts, the sensitive biological element (tissue, microorganisms, enzymes etc.), the transducer, and the detector element which works physicochemically. The major component of a biosensor is the transducer, which uses the physical changes of a reaction to produce an effect. Such physical changes could be thermal output, electrical potential change, redox reaction, electromagnetic radiation etc. The triggered electrical output from the transducer can then be amplified, processed, displayed and analyzed. Biosensors are a rapidly expanding field of study with an estimated annual growth rate of 60%, with the majority of the growth coming from the health-care industry. The biosensor concept can be traced back to Professor Leland C Clark Junior, who invented the oxygen electrode in 1956. He wanted to expand the range of analytes that we could measure in the body. His first experiment involved entrapping glucose oxidase enzyme in an oxygen electrode using a dialysis membrane. The observed decrease in oxygen concentration was proportional to glucose concentration. This is the first of many variations of the basic biosensor design that emerged out of Dr Clark's concept. Through the next several decades, the biosensor technology took off radically as a variety of new devices was discovered including enzymes, nucleic acids, and cell receptors. In looking at the historical development of this technology, 1980’s was certainly the inventive decade, with commercialization being the theme in the 1990’s. Biosensors’ primary functions in terms of research and commercial applications are identifying target molecules, identifying the availability of a suitable biological recognition element, and the potential for disposable detection systems to replace sensitive lab techniques. Examples of these functions include monitoring health related targets, detecting pesticides, detecting pathogens, and determining the level of toxicity in an organism or in the environment. The most widespread and commercialized example is the blood glucose biosensor, which uses an enzyme to break down blood glucose. Once broken, the biosensor transfers an electron to an electrode which is converted into a measure of blood glucose concentration. This process is especially important to diabetics to monitor glucose levels in their bodies. However, many biosensors are still not commercialized and most are still single analyte devices. In recent years, the development of biosensors for environmental and clinical applications has gained much interest from researchers, due 2007-11-20T07:29:37-05:00 http://75.150.148.189/free-essay/Microbial-Biosensors-–-Past,-Present-and-Future-33430.aspx Introduction A Hominid is any member of the biological family Hominidae, or more commonly known as the great apes. Hominids are categorised in these areas, Kingdom: Animalia, Phylum: Chordata, Class: Mammalia, Order: Primates, Suborder: Haplorrhini, Infraorder: Simiiformes, Parvorder: Catarrhini, Superfamily: Hominoidea, Family: Hominidae. The Hominidae family includes humans, chimpanzees, gorillas, and orangutans, as well as many other extinct species. The family has caused much division within the scientific community over the past few decades. Scientists use two main methods of determining the classifications of certain species, and what families they belong in. These methods are Genetics and Morphology. Genetics is the study of the DNA of certain species while Morphology is the study of the outward appearance of the species, including the skeletal structure as well as the social and personal habits. Specifically When this is applied to the Hominids, there appears to be a large contradiction. While there are some similarities between the morphology of Hominids, there is not enough evidence to suggest that they should be classified within the same biological family. However, genetic studies have shown that the DNA of humans and chimpanzees are very similar. In 2003, a study carried out by Morris Goodman of Wayne State University in Detroit found that 99.4 percent of the most critical DNA sites are identical in the equivalent human and chimp genes. The DNA of the two species is close enough to suggest that should definitely be classified within the same family, and it could even be suggested that they belong within the same genus. As a result, the Hominidae family has been subject to multiple revisions and changes. These changes have resulted in a varied use of the term Hominid. This poster should help to clear up the common misconceptions surrounding Hominids by providing a solid understanding of the entire Hominidae family. The Hominoidea Family Tree – Living Members The diagram on the right shows the family tree for Hominids, stemming from the Super family Hominoidea. The Hominoidea Super family contains both the families Hominidae and Hylobatidae. The Hylobatidae family is more commonly known as the lesser apes. The prominent species within the family Hylobatidae are the gibbons. The family is divided into four genera based on their diploid chromosome number, which is in brackets, Hylobates (44), Hoolock (38), Nomascus (52), and Symphalangus (50). Diploid Chromosomes are two complementary chromosomes, with one chromosome being derived from the mother and the other 2007-11-11T06:38:37-05:00 http://75.150.148.189/free-essay/Hominidae-Biological-Family-33408.aspx GLOBAL WARMING IN NORTH AMERICA The vast North American continent ranges from the lush sub-tropical climate of Florida to the frozen ice and tundra of the Arctic. Within these extremes are two wealthy industrialized countries with diverse ecosystems at risk. Yet the United States and Canada are two of the largest global emitters of the greenhouse gases that contribute to a warming climate. Examples of all 10 of the "hotspot" categories can be found in this region, including changes such as polar warming in Alaska, coral reef bleaching in Florida, animal range shifts in California, glaciers melting in Montana, and marsh loss in the Chesapeake Bay. For North America we have many more hotspots than for some other regions of the world, although impact studies have been emerging in larger numbers in recent years from previously under-studied regions. This higher density of early warning signs in the US and Canada is due in part to the fact that these regions have more readily accessible climatic data and more comprehensive programs to monitor and study environmental change, in part to the disproportionate warming that has been observed over the mid-to-high-latitude continents compared to other regions during the last century, and in part to capture the attention of North Americans who need to take action now to reduce greenhouse gas emissions. EVIDENCE Scientist by far and large accept that Earth’s climate is changing because of the amount of so-called greenhouse gases humans are pouring into the atmosphere. Most of those gases come from fossil fuels, particularly carbon dioxide, or CO2. And much of the scientific community thinks these gases are causing unnatural climatic warming that could have unimaginable effects on life. The consensus agrees that Earth has warmed by 1 degree Fahrenheit over the last century. That doesn’t sound like much, but consider that during the last ice age Earth was just 5 to 9 degrees cooler. And what may be most dramatic in the short run is the idea that changes in climate may also be leading to more severe weather. THEORY, FACT AND EVIDENCE In July 1997, President Bill Clinton launched a global warming awareness campaign, with headlines quoting him as saying it’s “no longer a theory, but now a fact.” But his full sentence reveals an important caveat: “The overwhelming balance of evidence and scientific opinion is that it is no longer a theory but now a fact that global warming is 2007-09-23T16:33:57-04:00 http://75.150.148.189/free-essay/-An-Overview-on-Global-Warming-in-North-America-33331.aspx The Jelly Cell is the second task of the Cells unit and is undoubtedly a more enjoyable assessment compared to cells online which was the previous task. Despite this, it is still an important assessment as it contributes five marks to the working scientifically criteria for term two. Because of its significance, a number of standards must be set to ensure the task is done to the best of my ability. Apart from accuracy, neatness, completeness, amount of technical detail, labelling of structures, originality and relationship of knowledge to cell construction, I would specifically like to focus on two main standards. Those are the accuracy of the justification of the model and the similarity between the shapes of the food products chosen to the real organelles. The table below shows the food products that I have chosen for each organelle. Organelle Item used to represent Diagram Reason for selection and function Cell membrane Solid plastic container The cell membrane is a thin layer of protein and fat that surround the cell. It is represented by a transparent plastic container so it is easier to see the organelles inside and more portable. Centrioles Raw spaghetti noodles The Centrioles is a small body located near the nucleus which creates microtubules. This is represented by a group of spaghetti noodles because the stick like shape of the centriole is also found in spaghetti noodles. Chromatin Plum meat The chromatin is found in the nucleus and contains DNA and RNA and various proteins that form chromosomes during meiosis. This is represented by the plum meat found inside the plum just like how the chromatin is found inside the nucleus. Cytoplasm JELLY The cytoplasm is the jelly-like material found around the nucleus. This is represented by the gelatine to fit the task. Golgi Apparatus Dried aniseed The Golgi Apparatus is a sac like organelle that produces the membranes that surround the Lysosome. This is represented by the dried aniseed because this product contains sac-like features like the Golgi Apparatus. Lysosome Peanuts Lysosomes are round organelles that contain digestive enzymes. This is represented by peanuts because they have a roundish feature as well. Mitochondria Cashew The mitochondria are a rod-shaped organelle that converts energy stored in glucose into ATP. This is represented by cashews because they rod-shaped. Nuclear Membrane Plum Skin The nuclear membrane surrounds the nucleus and is represented by the plum skin. This is quite convenient because the skin naturally surrounds the plum so no additional work is needed. Nucleolus Plum seed The plum seed symbolises the nucleolus because the seed is situated inside the 2007-07-19T10:37:31-04:00 http://75.150.148.189/free-essay/Jelly-Cell--33285.aspx Global Warming and Alternative Energy Sources People are inflicting major damage to the Earth’s environment, and if we don’t do anything to stop the destruction soon, the results could be devastating. Most people know about global warming and think it may be a serious problem in the future, but what most people don’t understand is that global warming is happening now. Every day we are feeling some of its destructive power, but we continue on our destructive path. Because of the dangerous effects of global warming, alternative energy sources need to be aggressively pursued. Finding and utilizing alternative energy sources may be the only way to combat the increase of global warming. “Scientists agree that the main reason for global warming is the depletion of the ozone layer surrounding the Earth due to increased levels of carbon dioxide and the increased release of greenhouse gas emissions.” Dr. Robert Watson from The Alliance of Concerned Scientists also adds, “These atmospheric concentrations of emissions are directly linked to human activities.” Fossil fuel emissions from gasoline and oil account for 52% of greenhouse gas emissions while coal burning energy plants and coal burning factories account for another 44% of emissions released (Samuelson 31). Overall, Americans are adding to global warming the most as we continue to be ‘energy hogs’ by driving gas-guzzling SUVs, and being careless with energy draining appliances in our homes. The destruction of forests around the world also adds to the problem by taking away the largest source of CO2 filters. Millions of trees are harvested each year due to increased demand for their byproducts, and, because of this, our environment suffers dramatically (Kenworthy 2). The United States accounts for over 51% of the energy used yearly through out the world. From 2000 - 2004 there was a 100% increase in greenhouse gas emissions in all established nations, and there seems to be no slowing down in the future with a projected 110% energy increase by 2010. At this rate scientists agree the world will be facing an energy crisis by 2020 if new energy sources aren’t found (McQuinn). The results of global warming are undeniably negative for the human race. Over the past ten years, the average surface temperature of earth has risen five degrees. Even though five degrees doesn’t seem like a major change, it has caused a disruption in the Earth’s fragile ecosystem (Watson 3). This increase has 2007-05-10T22:08:21-04:00 http://75.150.148.189/free-essay/Global-Warming-And-Alternative-Sources-33194.aspx Acromegaly and its Diagnosis Acromegaly (Greek for “appendage enlargement”) is a rare but very serious disease frequently referred to as “Gigantism” or “Giantism.” It is the direct result of an overproduction and secretion of the adenohypophyseal growth hormone GH. True to its name, the disease is characterized by an enlargement of the organs, bones, and soft tissues, as well as a thickening of the skin and bodily membranes; and is frequently difficult to diagnose, as symptoms often do not appear until middle age. Typically the disease results in heart failure caused by an enlargement of the heart, organ failure due to pressure or thickening of the outer membrane of the organ, or brain hemorrhaging caused by a benign or malignant pituitary adenoma. To date, there are three known forms of the disease: Cushing’s disease, Nelson Syndrome, and Prolactinoma. Each is characterized by different phenotypic attributes commonly linked by an enlargement of all or some particular body parts. Prolactinoma is the most frequently recognized form of giantism. It is characterized by an overall enlargement of the body, and was brought to public attention nearly twenty years ago by pro-wrestler and actor Andre the Giant, who later died of heart failure in the early 1990s. Nelson’s disease and Cushing Syndrome are similar to each other, however there is now controversy as to whether these two diseases are even linked to Prolactinoma since they are not commonly characterized by an overall enlargement of the body, but rather an extreme overproduction of soft and fatty tissue. These diseases cause thickening of the bones, skin, and soft tissue, but often appear after the person has finished growing, making the patient appear overweight and unable to speak and move with fluidity since the tongue and hands are hindered. All three diseases tend to have the same outcome: organ failure or brain hemorrhaging. In the past twenty years, controversy has arisen as to whether there are in fact three forms of the disease, what characterizes differentiation between each one, and how should each be treated accordingly. The problem is until recently, scientists have based their diagnoses almost entirely upon phenotypic characteristics and what is known about pituitary adenomata; only now are scientists beginning to analyze the genes and hormones involved on the micro level. The following articles examine methods in which 2007-04-23T04:14:20-04:00 http://75.150.148.189/free-essay/Acromegaly-and-its-Diagnosis-33102.aspx The Promises of Stem Cell Research From the monks practice of reincarnation to the Native American medicine man, civilization have searched for loop holes to cheat death and have gone to spontaneous measures to improve life. Modern day medicine has saved the life of thousands and given even more a healthier way of living. However, throughout the course of history, the practice of healing has taken a drastic change from a once religious threshold to a more scientific one. People hold more faith in a needle then they do in Allah, Buddha or the Lord. There is no considerable fault in this until we begin to forget our roots, morals and beliefs. Ethics, the reflection of almost all religion, has become jeopardized in the sense of today’s breakthrough medical techniques, to be more specific, stem cell research. Stem cells are the foundation of life, which form in a human embryo four days following conception. Experts suggest that stem cells have the potential to enhance and even save lives, but at the expense of killing an already fertilized organ. Is today’s society willing to put their moral beliefs at risk, to potentially save the life of another? There was a time when the word embryo was related to incidences such as fertility clinic mix ups, and cloning experiment. However, new technology raises a more ethical and political perspective around this comparatively trivial issue. Using spare embryos that were created with the intention of attempting to have a child, is somehow different from creating embryos with the intention of extracting their stem cells. For those who view embryos as human lives deserving of the same respect as a child, research that kills embryos is no more acceptable than would be research that kills adults. The U.S. Roman Catholic Bishops oppose the research as “immoral, illegal, and unnecessary. They say that life is sacred from the moment of conception. The opposite perspectives are those who view embryos as a collection of cells similar to other human tissue, and research is acceptable and relatively uncontroversial. The Presbyterian Church USA approves the research when the goals are, “compelling and unreachable by other means.” Comparing to an abortion, which is legal in most states, embryos even farther along the line are being killed. However, these were 2007-04-19T21:48:07-04:00 http://75.150.148.189/free-essay/The-Promises-of-Stem-Cell-Research-33070.aspx An occasional patient will ask: "Are x-rays safe?" Others will ask about the amount of radiation. As a radiologist you have a responsibility to give a reasonably honest and understandable answer to the patient. You can certainly explain that diagnostic x-rays are safe. There are no data to indicate otherwise. There is evidence that suggest that such low doses may actually reduce the chance of cancer.1 The question about amount is difficult to answer in an understandable way. First, because it is a rare x-ray unit that has a meter to measure the radiation to the patient and second, because scientific units for radiation dose are not understood. This article is to help you explain radiation to patients in words that they understand. In addition, I present evidence from various human studies to show that low level radiation, comparable to that from a radiograph, may be beneficial and even reduce cancer. Explaining radiation dose to a patient using the BERT concept Answering your patient's question about the amount of radiation would be easy if you knew the effective dose. However, it is unlikely the patient would be satisfied if your answer was "the mammogram will give you an effective dose of about 1 millisievert (mSv)." She probably would understand if you converted the effective dose into the amount of time it would take her to accumulate the same effective dose from background radiation. Since the average background rate in the U.S. is about 3 mSv per year, the answer in this case would be about four months. It is likely that she would understand and be satisfied with your answer. This method of explaining radiation is called Background Equivalent Radiation Time or BERT.2,3 The idea is to convert the effective dose from the exposure to the time in days, weeks, months or years to obtain the same effective dose from background. This method has also been recommended by the U.S. National Council for Radiation Protection and Measurement (NCRP).4 To calculate BERT, I recommend using the average background in the U.S. including contributions to the lung from radon progeny. This is assumed to be 3 mSv/y (300 mrem/y). The background in different parts of the U.S. varies about ± 50% from this value. This uncertainty is unimportant for explaining radiation to patients. The effective dose from common diagnostic x-ray procedures are typically less than the amount of radiation you 2007-04-18T02:35:31-04:00 http://75.150.148.189/free-essay/Are-X-Rays-Safe-32968.aspx DNA Gel Electrophoresis Research The main objective of this lab was to identify unknown plasmids by observation of their genotype and phenotype. We observed the plasmids phenotype by using it to transform bacteria. When the plasmid is in a bacterial host the antibiotic resistance gene can be expressed and impart resistance to the host. We also analyzed the genotype of the unknown plasmid by performing a variety of molecular genetic techniques such as predigestion, electrophesis in argose gel, staining with ethidium bromide, and finally a photograph of the gel, in order to compare the plasmid to a standard, to in turn deterimine the plasmids actual size and the sizes of its digestion fragments. By performing these experiments we found that our unknown plasmid in the blue tube was resistant to pKAN. We also found that the unknown plasmid when compared to a standard closely matched the size of digestion fragments, of pKAN, therefore our unknown plasmid was pKAN. Introduction There is growing concern that the control of infectious diseases is threatened by the upward trend in the numbers of bacteria that are resistant to multiple antibiotics in the medical armamentarium. Resistance costs money and human lives. Resistant infections are associated with increased morbidity, prolonged hospital stays, greater direct and indirect costs, prolonged periods during which individuals are infectious, and greater opportunities for the spread of infection to other individuals (2). In many developing countries, the availability and use of antibiotics are poorly controlled, which results in a high rate of resistance, particularly to the older antibiotics (2). The procedure used in our interpretation of Bacterial Transformation, is one that has a larger impact than our simple usage for finding unknowns when compared to knowns. This importance lies mainly in the medical field and more specifically in gene therapy. Using procedures, like this, Many human genes have been cloned in Escherichia coli or in yeast (4). This has made it possible - for the first time - to produce unlimited amounts of human proteins in vitro. Cultured cells (E. coli, yeast, mammalian cells) transformed with the human gene are being used to manufacture: insulin for diabetics, human growth hormone (GH), erythropoietin (EPO) for treating anemia, granulocyte-macrophage colony-stimulating factor (GM-CSF) for stimulating the bone marrow after a bone marrow transplant, adenosine deaminase (ADA) for treating some forms of 2007-03-05T14:22:19-05:00 http://75.150.148.189/free-essay/DNA-Gel-Electrophoresis-Research-32743.aspx Sleep: A Dynamic Activity Until the 1950s, most people thought of sleep as a passive, dormant part of our daily lives. We now know that our brains are very active during sleep. Moreover, sleep affects our daily functioning and our physical and mental health in many ways that we are just beginning to understand. Nerve-signaling chemicals called neurotransmitters control whether we are asleep or awake by acting on different groups of nerve cells, or neurons, in the brain. Neurons in the brainstem, which connects the brain with the spinal cord, produce neurotransmitters such as serotonin and norepinephrine that keep some parts of the brain active while we are awake. Other neurons at the base of the brain begin signaling when we fall asleep. These neurons appear to "switch off" the signals that keep us awake. Research also suggests that a chemical called adenosine builds up in our blood while we are awake and causes drowsiness. This chemical gradually breaks down while we sleep. During sleep, we usually pass through five phases of sleep: stages 1, 2, 3, 4, and REM (rapid eye movement) sleep. These stages progress in a cycle from stage 1 to REM sleep, then the cycle starts over again with stage 1 (see figure 1). We spend almost 50 percent of our total sleep time in stage 2 sleep, about 20 percent in REM sleep and the remaining 30 percent in the other stages. Infants, by contrast, spend about half of their sleep time in REM sleep. During stage 1, which is light sleep, we drift in and out of sleep and can be awakened easily. Our eyes move very slowly and muscle activity slows. People awakened from stage 1 sleep often remember fragmented visual images. Many also experience sudden muscle contractions called hypnic myoclonia, often preceded by a sensation of starting to fall. These sudden movements are similar to the "jump" we make when startled. When we enter stage 2 sleep, our eye movements stop and our brain waves (fluctuations of electrical activity that can be measured by electrodes) become slower, with occasional bursts of rapid waves called sleep spindles. In stage 3, extremely slow brain waves called delta waves begin to appear, interspersed with smaller, faster waves. By stage 4, the brain produces delta waves almost exclusively. It is very difficult to wake someone during stages 3 and 4, which together are called deep sleep. There is no eye movement or muscle 2007-02-17T07:32:34-05:00 http://75.150.148.189/free-essay/Understanding-Sleep-32637.aspx In every part of our body there reigns a tiny yet complex life. An examination under the microscope into the depths of any human organ brings us face to face with an astounding miracle of creation: millions of tiny living things that have come together to make up that organ are engaged in arduous activity. These tiny beings are cells, the basic units of life. Not only man but also all other living things are composed of these microscopic living beings. There are about 100 trillion cells in the human body. Some of these cells are so tiny that even 1 million of them together hardly cover a space as large as the pointed end of a pin. Despite this, however, the cell is by far the most complex structure mankind has ever encountered, as is also agreed by the scientific community. Containing many secrets hitherto undiscovered, the cell of a living thing also constitutes the greatest impasse for the theory of evolution. That is because the cell is one of the most striking pieces of evidence that human beings and all other living beings are not the products of coincidences, but are created by a Creator. In order for the cell to survive, all the basic components of the cell, each performing many vital functions, have to be intact. If the cell came into existence by evolution, then millions of its components had to simultaneously exist in the same place and they had to come together in a particular order and plan. Since this is utterly implausible, such a structure has no explanation other than "creation." One of the leading evolutionists, Alexander Oparin, expressed the deadlock the theory of evolution encountered in this way: "Unfortunately, the origin of the cell remains a question which is actually the darkest point of the complete evolution theory." (Alexander I. Oparin, Origin of Life, (1936) NewYork: Dover Publications, 1953 (Reprint), p.196) The English mathematician and astronomer Sir Fred Hoyle made a similar comparison in one of his interviews published in Nature magazine dated November 12, 1981. Although an evolutionist himself, Hoyle said that the odds that higher life forms might have emerged in this way was comparable to the odds of a tornado sweeping through a junk-yard assembling a Boeing 747 from the materials in it. This means that it is not possible for the cell to come into being by coincidence and therefore, it must 2007-01-27T17:24:23-05:00 http://75.150.148.189/free-essay/The-Miracle-of-Design-in-the-Cell-32459.aspx Defence is an issue that has to be given top priority by a country for the continuance of its existence. Nations have always to watch out for all kinds of internal and external threats, assaults, risks of wars and terrorist actions. This is why they allocate a great part of their official budgets to defence. Armies are provided with the most advanced aircraft, ships, and arms, and the forces of defence are always kept at the highest level of preparedness. The human body is surrounded by a great number of enemies and threats. These enemies are bacteria, viruses, and similar microscopic organisms. They exist everywhere; in the air we inhale, the water we drink, the food we eat, and the environment in which we live. What most people are not aware of is that the human body has an excellent army, the immune system, which fights against enemies. This is a real army made up of many "soldiers" and "officials" with different assignments, who are specially trained, employ high technology and fight with conventional and chemical weapons. Every day, even every minute, a permanent war is fought between this army and the enemy forces, but away from our knowledge. This war can also be in the form of minor, local skirmishes as well as battles in which the whole body is involved and alarmed. We call these battles "diseases". The general conduct of this war almost never changes. The enemy attempts to fool the other side by camouflaging itself when intruding into the body. The trained investigative forces are assigned by the defence to identify the enemies. The enemies are identified and appropriate weapons are produced to exterminate them. Then there is close contact, the defeat of the enemy, cease-fire, and clearance of the battleground. Last, there is storage of every type of information about the enemy as a precaution against the possibility of a later attack.... Now let us examine this interesting war closer. THE BESIEGED CASTLE: THE HUMAN BODY We can liken the human body to a castle besieged by enemies. The enemies look for various ways to invade this castle. The human skin is the wall of this castle. The substance of keratin in the cells of the skin is an impassable barrier for bacteria and fungi. Foreign substances that reach the skin cannot pass through this wall. Moreover, although the outer layer of skin that contains keratin is continuously rubbed 2007-01-27T17:13:04-05:00 http://75.150.148.189/free-essay/The-Miracle-in-the-Defence-System-32457.aspx And We have enjoined upon man goodness towards his parents: His mother bore him by bearing strain upon strain, and his weaning was in two years: “[Hence, O man,] be grateful to Me and to your parents; to Me is the eventual coming.” (Qur’an, 31:14) Mother’s milk is a matchless compound created by Allah to meet the baby’s nutritional needs and protect it against possible infections. The balance of the nutriments in mother’s milk is at ideal levels and the milk is in the ideal form for the baby’s immature body. At the same time, the mother’s milk is also very rich in nutrients which accelerate the growth of brain cells and the development of the nervous system. 1 Artificial baby foods prepared with present-day technology cannot replace this miraculous food. The list of advantages to the baby provided by mother’s milk is being added to every day. Research has shown that babies who are fed mother’s milk are particularly protected against infections concerning the respiratory and digestive systems. That is because the antibodies in mother’s milk provide a direct defence against infection. Other anti-infection properties of mother’s milk are that it provides a hospitable environment for “good” bacteria called “normal flora” thus constituting a barrier to harmful bacteria, viruses and parasites. Furthermore, it has also been established that there are factors in mother’s milk which arrange the immune system against infectious diseases and allow it to function properly. 2 Since the mother’s milk has been specially designed, it is the most easily digestible food for babies. Despite being nutritionally very rich, it is easily digested by the baby’s sensitive digestive system. Since the baby thus expends less energy on digestion, it is able to use that energy for other bodily functions, growth and organ development. The milk of mothers who have had premature babies contains higher levels of fat, protein, sodium, chloride and iron to meet the baby’s needs. Indeed, it has been established that the functions of the eye develop better in premature babies fed on mother’s milk and that they perform better in intelligence tests. In addition, they also have a great many other advantages. One of the ways in which mother’s milk is important to the development of the new-born baby is the fact that it contains omega-3 oil alpha linoleic acids. As well as being an important compound for the human brain and retina, it is also of great 2007-01-27T17:08:49-05:00 http://75.150.148.189/free-essay/Mother’s-Milk-a-Miraculous-Mixture-32456.aspx In the two widest-ranging exercises on mapping the galaxies carried out to date, scientists have made findings that offer serious support for the Big Bang theory. The results of the research were presented at the winter conference of the American Astronomical Society. The wide extent of the distribution of galaxies is evaluated by astrophysicists as one of the most important legacies from the first phases of the universe to have come down to the present day. It is therefore possible to refer to the information on the distribution and location of the galaxies as "a window opening onto the history of the universe." In their research that lasted several years, two independent teams, composed of British, Australian and American scientists, produced a three-dimensional map of some 266,000 galaxies. The scientists compared the data they collected on the distribution of the galaxies with the data for the Cosmic Background Radiation emitted everywhere in the universe, and made important discoveries regarding the origin of galaxies. Researchers analysing the data concluded that the galaxies formed where matter that formed 350,000 years after the Big Bang relatively clustered together, and then assumed their shape under the influence of the force of gravity. According to the Big Bang theory, everything began from the explosion of a point of infinite density and zero volume. As time passed, space expanded and the gaps between heavenly bodies grew. The findings in question confirmed the Big Bang theory, which states that the universe began from the explosion of a single point of zero volume and infinite density some 14 billion years ago. This theory has constantly been confirmed by tests consisting of decades of astronomical observations, and stands unrivalled on the most solid of foundations. The Big Bang is accepted by the great majority of present-day astrophysicists, and constitutes scientific verification of the fact that God created the universe from nothing. In its ten-year-long research, the Anglo-Australian Observatory in the Australian state of New South Wales determined the positions in space of 221,000 galaxies by means of a three-dimensional mapping technique. The survey, which was performed with a 3.9 metre diameter telescope at the observation post, was almost ten times larger than any previous such study. (1) Under the leadership of Dr. Matthew Colless, director of the observatory, the team of scientists first determined the position of galaxies relative to one another and the distances between them. Then they modelled 2007-01-27T17:02:56-05:00 http://75.150.148.189/free-essay/The-Big-Bang-Echoes-through-the-Map-of-the-Galaxy-32455.aspx Nobody looking at the patterns in peacock feathers can avoid being amazed at their beauty. One of the latest pieces of research by scientists has revealed that there is an astonishing design at the basis of these patterns. Chinese scientists have discovered a delicate mechanism of tiny hairs in peacock feathers filtering and reflecting different wavelengths of light. According to a study performed by Fudan University physicist Jian Zi and colleagues, published in the journal Proceedings of the National Academy of Sciences, the feathers' bright colors are produced not by pigments, but by tiny, two-dimensional crystal-like structures. (1) Zi and his colleagues used powerful electron microscopes to reveal the basis of the colors in the feathers. They examined the barbules of the male green peacock (Pavo rnuticus), in other words the even smaller micro hairs that come off of barbs emerging from the central stem of the feather. Under the microscope, they encountered the lattice design in the black-and-white picture to the right. This consisted of rods made of melanin, a protein, bound together with keratin, another protein. The researchers observed that these two-dimensional structures, each with a width hundreds of times thinner than a human hair, were arranged one behind the other on the micro hairs. Using additional optical examinations and calculations, the scientists examined the spaces between the crystals and their effects. As a result, it was revealed that the dimensions and shapes of these spaces in the lattice led to light being reflected at slightly different angles and thus to a variation in color. "The male peacock tail contains spectacular beauty because of the brilliant, iridescent, diversified, colorful eye patterns," said Zi, who continued, "when I watched the eye pattern against the sunshine, I was amazed by the stunning beauty of the feathers." (2) Zi stated that until their study, the exact physical mechanism producing the colors in peacock feathers had not been known, and that although the mechanisms they had revealed were simple, they were absolutely ingenious. Obviously, there is a very specially regulated design in peacock feather patterns. The tiny lattices and spaces between them are of the greatest importance in this design. The adjustment between the spaces is particularly striking. Were these not so arranged as to reflect light at slightly different angles to one another, then this variation in color would not take place. The greater part of the color in the peacock feather 2007-01-27T16:55:29-05:00 http://75.150.148.189/free-essay/The-Physical-Basis-of-the-Beauty-in-Peacock-Feathers-Reveale-32454.aspx Each and every species on Earth has been created with miraculous characteristics and wondrous skills. Even in one single living species, we can find abundant proof of God’s magnificent creation. According to one verse of the Qur’an: There is no creature crawling on the Earth or flying creature, flying on its wings, who are not communities just like yourselves—We have not omitted anything from the Book—then they will be gathered to their Lord. (Qur’an, 6:38) This verse draws our attention to birds which, of all living creatures, are worthy of special consideration and observation. There are approximately ten thousand different species of birds, many of which have miraculous characteristics. Wherever we live, we may encounter many of these creatures and can admire the different aspects of each variety. They exhibit countless examples of the evidence of creation, through their aesthetic appearance, their perfect flying mechanisms, their expertise in migration, their nest-making skills and their self-sacrificing behavior. Meanwhile, other species of birds are created with a special aptitude for forming social groups. Many varieties live together as a community, warn one another of danger, work collectively to find food and shelter, and make various sacrifices to help each other out in any number of ways. (For detailed information, see Harun Yahya, Devotion Among Animals: Revealing the Work of God). As God pointed out in the Qur’an, these creatures are capable of establishing their own form of communication and performing in cooperative ways the duties inspired in them by God. Some birds distinguish themselves by their superior intelligence and special talents. These particular species are defined as birds that can imitate sounds, include the parrots, songbirds, and hummingbirds. Many of us have heard about, seen on television or even personally witnessed these birds’ ability to talk. However, we may not have considered what a great miracle it is that these creatures can mimic in this way, or to the perfection of the way in which God has created them. These creatures’ being hatched with their ability to talk or imitate sounds is one of the miracles of creation and, at the same time invalidates the claims of evolutionary theory. The Special Design which Enables Birds to Produce Sound Talking, or even imitating sound, is not just a simple matter of opening and closing the mouth, as some people believe. A complex system is required for this action to take place, and 2007-01-27T16:51:14-05:00 http://75.150.148.189/free-essay/The-Miracle-of-Talking-Birds-32453.aspx The earth is a living planet where many complex systems run perfectly without stopping at all. When compared to other planets, it is evident that in all its aspects the earth is specially designed for human life. Built on delicate balances, life prevails in every spot of this planet, from the atmosphere to the depths of the earth. Exploring only a few of the millions of these delicate balances would be sufficient to show that the world we live in is specially designed for us. One of the most important balances in our planet is revealed in the atmosphere that surrounds us. The atmosphere of the earth holds the most appropriate gasses in the most appropriate ratio needed for the survival not only of human beings, but also of all the living beings on the earth. The 77% nitrogen, 21% oxygen and 1% carbon dioxide as well as other gasses readily available in the atmosphere represent the ideal figures necessary for the survival of living beings. Oxygen, a gas that is vital for living beings, helps food to be burned and converted into energy in our bodies. If the oxygen quantity in the atmosphere were greater than 21%, the cells in our body would soon start to suffer great damages. The vegetation and hydrocarbon molecules needed for life would also be destroyed. If this quantity were less, then this would cause difficulties in our respiration, and the food we eat would not be converted into energy. Therefore, the 21% oxygen in the atmosphere is the most ideal quantity determined for life. No less than oxygen, other gasses like nitrogen and carbon dioxide are also arranged in the ideal quantity for the needs of living beings and the continuity of life. The amount of nitrogen in the atmosphere has the ideal ratio to balance the harmful and burning effects of oxygen. This ratio represents the most appropriate value required for photosynthesis, which is essential for life's energy supply on the earth. Moreover, the amount of carbon dioxide has the most appropriate value that is needed to maintain the stability of the surface temperature of the earth and to prevent heat loss especially at night time. This gas, comprising 1% of the atmosphere, covers the earth like a quilt and prevents the loss of heat to space. If this amount were greater, the temperature of the earth would increase excessively, causing climatic instability and posing 2007-01-27T16:44:17-05:00 http://75.150.148.189/free-essay/The-Delicate-Balance-on-Earth-32452.aspx Living beings have to reproduce to continue their species. However, reproduction by itself often proves insufficient, because if living things fail to provide adequate care for their offspring, the newborn cannot survive. In other words, if living things did not feel the need to protect and look after their offspring and did not do this successfully, newborn creatures would not be able to look after themselves and would soon die. When we look at nature, we see the majority of living things display amazing self-sacrifice in order to protect and provide the best care for their offspring, incomparable to any form of sacrifice shown by human beings. Furthermore, these living things risk their lives for their young without a moment's hesitation. So, how did such self-sacrifice in animals develop? Evolutionists claim that self-sacrifice displayed by living things, especially that shown towards their offspring, is instinctive behavior. What then does the word instinct mean? Evolutionists define instinct as a sense of intuition inherent in living things. They claim that an inner voice whispers to a spider, a bird, a lion or a tiny insect to practice self-sacrifice to keep the generations going. In reply to a question regarding the source of this voice, they desperately say "mother nature". In the view of evolutionists, every phenomenon in nature is a miracle of nature. However, it is evident that this claim is futile and meaningless, because nature itself, is already a created entity consisting of the stones, flowers, trees, rivers and mountains familiar to all of us. It is obvious that these entities cannot come together to furnish a living being with a new trait, which is a product of intelligence. As a matter of fact, even Darwin himself was aware of this logical failure from the very beginning. In his book The Origin of Species, which he wrote in 1859, he expressed his self-doubt about his own theory in the following words: So wonderful an instinct as that of the hive-bee making its cells will probably have occurred to many readers, as a difficulty sufficient to overthrow my whole theory. (Charles Darwin, The Origin of Species, p. 233) Research conducted by scientists on living things has revealed that they live in an astounding harmony, coordination and collaboration with one another. Wherever one turns in nature, one is likely to see examples of this. For instance, some little birds utter a shrill alarm call when they see 2007-01-27T16:37:23-05:00 http://75.150.148.189/free-essay/Self-Sacrifice-in-Animals-32451.aspx Some spiders hunt in even the most unexpected environments. For example, the hunting field of the water-spider Dolomedes is the surface of water. This spider is mostly to be found in shallow places such as marshes and ditches. The water-spider, which lacks good eyesight, spends most of its time by the side of the water spinning threads and spreading them over its surroundings. These serve two functions at the same time: they are a kind of warning to other spiders, setting the limits of its own territory, and they also form an escape route in the event of unexpected danger. The spider's most frequently used hunting method is to put four of its legs on the water while the other four hold on to dry land. While doing this, it employs a most clever technique to avoid sinking. The spider covers those of its legs which will go into the water with a water-proof coating by passing them through its fangs. It then approaches the edge of the water. Pushing its body down with great care, it moves on to the surface of the water. It places its fangs and feelers under the water in such a way as not to disturb the surface. It waits for a living creature to approach, with its eyes looking around it and its legs feeling for vibrations in the water. To feed itself, the spider needs to find prey at least the size of the "Golyan" fish. When the spider is hunting, it stays motionless until the fish comes within 1.5 centimeters of its jaws. Then it suddenly enters the water, catches the fish in its legs, and bites it with its venomous fangs. Then, in order to stop the fish, which is much bigger than it, from dragging it under the water, it immediately turns upside down. The venom quickly takes effect. It not only kills the prey, but also dissolves the prey's internal organs, turning them into a kind of soup and making them easy to digest. When the prey is dead, the spider drags it on to the shore and feeds. (Science and Technology Gorsel Science and Technology Encyclopedia, p. 494, 495) At this point various questions spring to mind. How did the spider come by that wax which stops it sinking? How did it learn to coat its legs with it against the risk of sinking? How did the spider come by the 2007-01-27T16:33:17-05:00 http://75.150.148.189/free-essay/Spiders-Fishing-Techniques-32450.aspx Communication and Signaling in the Language of Birds Scientific research has revealed that throughout the living world, communication is just as important as it is to human beings. Countless living things lack the capacity for human speech, yet they employ entirely different methods in order to communicate with each other—and even with other species. Some of the most dramatic examples of this is displayed by birds. The astonishing behavior and ability to communicate that birds exhibit also totally invalidates the claims of the theory of evolution. All forms of life on Earth have been created with miraculous properties and astonishing abilities. The examination of just one single species is enough to reveal hundreds of proofs of God’s magnificent creation. In one verse of the Qur’an, Allah reveals that: There is no creature crawling on the earth or flying creature, flying on its wings, who are not communities just like yourselves—We have not omitted anything from the Book—then they will be gathered to their Lord. (Qur’an, 6: 38) The birds to which this verse draws our attention notice are one of the living communities that we need to examine and reflect upon. There are roughly some 10,000 species of bird in the world, each of which possesses its own miraculous features. Wherever you may live, you can see a great number of these feathered creatures and can observe different and extraordinary properties in each and every one. With their attractive appearances, flawless flight mechanisms, expertise on the routes and timing of migrations, ability to build nests and altruistic behavior toward their young and to one another, birds possess countless proofs of the fact of creation. Their ability to communicate is another of these. Birds' Sense of Hearing For birds to display their talents in communicating by sound, song—and in the case of some birds, words— they require excellent hearing. At critical times in their lives, their sense of hearing becomes particularly important. Experiments have shown that in order for birds to learn the distinctive song of their own species, they need an auditory feedback system. Thanks to this system, young birds learn to compare the sounds they produce themselves with the patterns of a song they have memorized. If they were deaf, it wouldn't normally be possible for them to sing recognizable songs. (1) Birds' ears are well equipped for hearing, but they hear in a different way from us. For them to recognize 2007-01-27T16:16:05-05:00 http://75.150.148.189/free-essay/A-Miracle-of-the-Living-World-32449.aspx Every second, more processes than can be counted are carried out in the bodies of all living things. So complex and detailed are these processes that at every stage, the intervention of “super-regulators” is essential to control the whole system that maintain order and accelerate events. These super-regulating chemicals in the human body are enzymes. Every living cell contains thousands of enzymes, each of which performs its own tasks, such as assisting with the copying of DNA, breaking down foodstuffs and producing energy from them, and constructing chains of compounds from simple molecules. Enzymes are produced by mitochondria inside each cell. Large parts of enzymes consist of proteins, the rest of are vitamins and vitamin-like substances. Were it not for these enzymes, none of our functions, from the simplest to the most complex, could take place, or else would occur so slowly as to stop altogether. In either case, the result would be the same—death. We could not speak, eat, digest, see or even breathe– in short, we could not live. Enzymes’ most important tasks are to initiate, halt and accelerate various chemical reactions in the body. As the cells perform their functions, the chemicals inside them must react accordingly. Higher temperatures are needed to initiate most chemical reactions. Yet such high temperature could pose a danger to living cells, causing them injury or death. The solution to this dilemma lies in enzymes. An obvious miracle of creation, enzymes manage to initiate or accelerate chemical reactions even in the absence of high temperature, yet as catalysts, they do not enter into—or are themselves changed—by these reactions. Take one example from your daily life of how enzymes accelerate the processes taking place within your body: Thanks to an enzyme involved in the removal of carbon dioxide from the blood as you inhale, you do not suffocate. An enzyme known as anhydrase accelerates the process of cleansing carbon dioxide by a factor of 10 million times! At this speed, the anhydrase can transform 36 million molecules every minute. The Body’s Rapid and Economical Production Vehicles Enzymes permit vital reactions to take place as quickly as possible, and also to exploit the body’s energy in the most efficient way. If you compare the human body to a factory, with the many enzymes working within its cells as various means of production, no source of energy would be able to run with that factory. Because the level 2007-01-27T16:03:58-05:00 http://75.150.148.189/free-essay/Enzymes-that-Perform-36-Million-Processes-a-Minute-32448.aspx Breakdown of the Parts of a Human Cell There once was a guy named Timmy. Timmy was attending college at the University of Wisconsin. At the college, he was going through a biology class and was having a hard time comprehending the theory of cells. He didn’t understand what all the cell parts were and what their functions were. He hoped that as time went on, he’d eventually catch on. Well any ways, Timmy was in desperate need of some money. He needed some food for his dorm and wanted a new bike to travel around on. While he was flipping through the classified ads, he found a job that sounded interesting to him. Subway needed some help with making sandwiches and working at the register. Timmy thought this would be an easy way for him to make some quick and easy money. The next day, Timmy drove to the nearest Subway and got an application. He filled it out and turned it in within a few hours. In a matter of two days, he got a call back saying he was hired! He was ecstatic! Finally, he’ll be able to have some money. Timmy was really excited and he was looking forward to his first day at work. The manager asked him if he could start as soon as tomorrow and Timmy agreed. While he was excited, he was nervous at the same time. He didn’t want to screw up his first day on the job. The manager told him not to worry though because the job isn’t too tough and he’ll find help if he needs it. Timmy went to bed that night on a good note looking forward to his first day in the working field. Timmy woke up early the following morning and got himself ready for work. He was supposed to be there at 11:00 a.m. but he wanted to get there a little early so he would look better. While he was getting ready, he realized that he totally forgot about his quiz on cell parts that he was scheduled to have that night. He didn’t know what to do!! Since he had to be at work in a short time, he knew he didn’t have time to study. Timmy 2007-01-09T04:10:15-05:00 http://75.150.148.189/free-essay/Breakdown-of-the-Parts-of-a-Human-Cell-32323.aspx Dangers of the Greenhouse Effect When a person starts their car or does a very small and simple thing the last thing that they are thinking of are the consequences it has to the atmosphere. Because of the continuous changing of the society, the earth has to get used to several different problems. Even though the atmosphere is known to be good because it protects us from the deadly radiation from the sun, it also takes that same heat and engulfs the earth in it. The greenhouse effect refers to the light energy that is trapped by the gases in the atmosphere, and the gases convert the light energy into heat energy. Although most of this heat energy redirected into space, the earth traps enough of it to heat the atmosphere, or enough to make a temperature that can support life. That is the actual greenhouse effect, but when it is put to perspective in our days, scientists believe it is not very good. Scientists think that the greenhouse effect will become uncontrollable. They believe that since there is so much activity happening on earth, that it will produce more of the greenhouse gases to put in the atmosphere. And the more gases there are then the more heat there will be trapped in the atmosphere. The gases that are trapped in the atmosphere that make the greenhouse effect are natural gases such as carbon dioxide, methane, nitrous oxide, and halocarbons. The greenhouse effect can be harmful, but it can also be helpful. Since the climate gets hotter and hotter each year, this will cause the vegetation to die, and without vegetation, the animals that rely on the vegetation, herbivores, and then the animals that rely on eating the herbivores, carnivores, die out and then the whole eco-system is messed up. Also causes problems by raising the temperature on the planet. Even though the raise in the temperature is not much, the earths eco-system is very easily damaged. The Inter-Governmental Panel has predicted that by the year 2025, the temperature will go up by one degree and that would almost destroy the North American corn crop, which produces much of the world’s grain. All of that results in much higher grain prices and less grain for the third world countries than the small amount they 2006-12-29T15:52:12-05:00 http://75.150.148.189/free-essay/Dangers-of-the-Greenhouse-Effect-32154.aspx Dangers of Biological Warfare Since man first started using his hands to make tools and weapons, he has always struggled to be more powerful and have better weapons than his enemies. Today is no different. Perhaps one of the newest, most publicly known type of weapon being created and tested is biological warfare. This type of warfare is believed to be the best and most deadly of all weapons, however, the big question is, how safe is it, and what are its effects on the environment? In James Powlik’s Sea Change, the author clearly states that biological warfare is not safe and that it is harmful to the environment. Three good examples of this are: the Pfiesteria in Powlik’s novel, its effects on humans, and its effects on animals. Firstly, just by taking a look at the Pfiesteria will show just how dangerous it really is. Although the Pfiesteria in Powlik’s novel is a semi-fictitious organism, there are other biological weapons similar to it. The Pfiesteria is described as follows: Taxonomic genus of dinoflagellate first described in the early 1990’s and found in the Gulf Stream waters of the Atlantic Ocean. Pfiesteria prefers warm, brackish conditions and has been linked to seasonal fish kills in nutrient-laden estuaries of the U.S. mid-Atlantic states. It consumes other algae, sometimes using the chloroplasts for photosynthesis. The organism has been described as having up to 24 distinct life stages and produces at least two toxins that act offensively rather than as a passive deterrent. One, a water-soluble neurotoxin, is used to stun prey, while a second, fat-soluble toxin ulcerates and destroys tissue. (Powlik, 478) This is a description of the real Pfiesteria, but the Pfiesteria in Sea Change is not all that different from it. The only difference is the semi-fictitious Pfiesteria can harm humans and animals larger than cod-size fish, and can survive in the Pacific Ocean near Canada. On top of this, both types of Pfiesteria can form a protective layer called a cyst when the conditions they are living in at the time are no longer ideal. This means that they go into a type of ‘hibernation’ until the conditions are livable. They can ‘hibernate’ in this state for more than 20 years. This can obviously be a problem because people might think that it 2006-12-29T15:50:54-05:00 http://75.150.148.189/free-essay/Dangers-of-Biological-Warfare-32153.aspx Potential Health Benefits of the Human Genome Project From World News Tonight to the cover of Science magazine, the Human Genome Project (HGP) has attracted much attention. For the past few years, the HGP has been at the forefront of science news and publicity. It has been built up to be the largest breakthrough in the history of modern science. This project will revolutionize the practice of medicine by drastically improving the treatment and/or prevention of numerous diseases and defects. The HGP is in the process of sequencing all the protein bases of DNA in a human, and although each person’s DNA is unique, scientists agree that there is a certain sequence common to everyone. Finding this sequence and recognizing what parts of the DNA do what is the ultimate goal of the HGP. This task, developed in 1990, didn’t just seem difficult at its time of conception; it seemed impossible. However, expected advancements in technology have occurred along the way, placing the task within reach. What will stem from these findings will for sure make a significant impact on modern medicine. The Human Genome Project is an international research program attempting to construct detailed genetic maps of the human genome, to determine the sequence, to localize the approximately 100,000 genes in the genome, and to be able to analyze all of this (“The HGP” 1). The term genome refers to the sum of all genes, which are made of DNA (“Speed” 7). DNA is made up of four similar chemicals (called bases), which are also called amino acids. They are called guanine, cytosine, thymine, and adenine. These four amino acids are repeated in a certain order throughout three billion pairs in the human genome (“Human” 5). It is this certain order that makes each person unique. Scientists do say, however, that humans are enough alike that there is a genomic sequence that can function as a standard for all of humanity (“Speed” 2). To find this sequence is the major goal of the HGP. Jack Robertson, in his article in the Sacramento Business Journal paints a picture of the future with the HGP in hand. Cancer will be gone. Birth defects will disappear like childhood diseases did a generation ago. An understanding of the entire sequence of 2006-12-19T16:58:39-05:00 http://75.150.148.189/free-essay/Potential-Health-Benefits-of-the-Human-Genome-Project-32088.aspx Issues with Animal Cloning The theory of being able to make a genetic copy (a clone) of another animal has been around for quite a while. But animal cloning has been a scientific breakthrough only in recent years. Through cloning and genetic engineering, scientists have been able to perform incredible medical procedures that could one day help diseased people all over the world. There are many steps involved in cloning, and many precautions must be used. Scientists have found many useful benefits to animal cloning in many areas of science, and these may one day help mankind in the future. In order for animal cloning to be successful, many steps are necessary. There are three common ways of cloning animals. One way is by separating the embryo. This involves taking out a fertilized ovum, waiting until a cell cultivates into four cells, separating these cells, then putting the ovum back into the animal. Each of the cells has the exact same DNA. Another way of cloning animals is nuclear transplantation (taking the cell from a fertilized ovum). This is done by taking out a fertilized ovum from an animal when nuclear splitting starts, then by using enzymes, the nucleus will be cut one by one, then a cell is taken out of an unfertilized ovum that came from a different animal and a cell from the fertilized ovum is put in to replace it, then an electrical shock is given to the unfertilized ovum so that the cell and unfertilized ovum come together to become a fertilized ovum. This ovum is put into another one of the animal so that it can give birth to the newly fertilized egg. Another common method of cloning is done by taking cells from parts of the body. First, a cell is taken from an animal, then cell is cultivated so it will become active again, then an unfertilized ovum is prepared, then a cell is taken from it and replaced by the original cell from the animal being cloned. By using electrical shock the cell and ovum come together to become fertilized, making a cloned egg. This cloned egg is inserted into an unfertilized ovum to give birth to the clone. As it can be seen, nuclear transplantation and taking cells from parts of the 2006-12-19T03:52:49-05:00 http://75.150.148.189/free-essay/Issues-with-Animal-Cloning--32069.aspx Bioengineering Food In the past decade, we have become witness to the creation to the birth of “ Dolly, the lamb, ” in-vitro fertilization, organ transplants, and nutritionally enhanced food, all of which fall under the very controversial topic of cloning. These dramatic advances in biotechnology have spurred many ethical debates as well as questions by many philosophers, researchers, scientists, as well as everyday people in dire need of these advancements for medical reasons. On the one hand, from a utilitarian perspective, bioengineering is essentially creating, “ the greatest good for the greatest number,” by possibly eliminating life threatening diseases and prolonging human life. On the other, it provokes fear throughout humans that one-day biotechnology may advance so far as to be able to clone human beings. Despite these fears, we can see how the bioengineering of food is a positive advancement in technology. Life can be prolonged and enhanced with cures for diseases; higher yielding crops and more nutritionally enhanced food, benefits all of us. First of all, let us take an ethical standpoint. Based on the famous nineteenth-century English philosopher John Stuart Mill, “The purpose of a moral action is to achieve the greatest overall happiness, and to create the greatest good for the greatest number.” (Donaldson, p. 5) The bioengineering of food essentially creates the greatest good for the greatest number; for obvious reasons, all humans need food, and more nutritious food at that. The influence of bioengineering in crops could result in food that is more nutritious, better tasting, as well as creating a higher yields of crops. This bioengineered food can help to provide the poor with food at a more rapid pace. As, with the use of bioengineering, scientists are able to genetically alter crops through a process known as selective breeding. In this process, scientists can create crops having only desirable traits, thereby eliminating the undesirable traits. You may ask, why can’t we just grow crops in the traditional manner? According to the International Food Information Council Foundation, ‘Rather than spending 10-12 years to breed plants in the traditional manner, mixing thousands of genes to improve a crop plant, modern crop breeders can select a specific genetic trait from any pant and move it into the genetic code of another plant through biotechnology.’ (Food Biotechnology Inc., Background) Biotechnology, according to the International Food Information Council foundation, is in essence helping 2006-12-19T03:11:54-05:00 http://75.150.148.189/free-essay/Bioengineering-Food-32054.aspx In Favor of Increased Cloning Research The announcement of the cloned ewe, Dolly, in 1997 by scientists in Scotland, was a shock to the entire world. The idea of cloning wasn’t new, but at the time still seemed farfetched to most. As John Greeney stated “We had not, as a species, ever truly considered the likelihood that human reproduction would fall so fully under the hand of technology” (1). However, once the reality of this controversial practice set in, scholars and common people alike began to debate the pros and cons of cloning from one end of the globe to the other. With morals and ethics at the forefront of the debate, people were, and still are, quite divided, as those are touchy subjects of personal opinion. Governments around the world quickly echoed the squeamishness of the public as many countries enacted bans on experiments that used the cloning of human cells. The United States was no exception as the federal government enacted laws to ban all experiments that involve the cloning of human cells. However, it is clear that the cloning of human cells has become inevitable. In response, the United States should draft laws that only allow for therapeutic cloning and cloning for infertile couples, with an agency that will oversee all of these practices. If this were to occur, there would be a higher quality of life throughout the country. To start, the cloning of human beings appears to be inevitable. Scientists, doctors, and researchers around the world have been successfully cloning and manipulating animals for years as they wait for the moratorium on human cloning to come to an end. With each attempt at cloning animal cells, these doctors and scientists are learning more about cloning and developing hypotheses on how to apply their findings to humans. The only thing standing in their way of actually applying their findings to human beings are the government bans which are to soon be lifted. “Now that the technology exist to easily modify genes in animals, scientists and bioethicists realize that there is very little standing in the way of applying this genetic technology to human beings” (Richardson 1). Also, in the United States, the federal government gave federal funds to the Oregon Health Sciences University where, “Scientists…modified the genetic make-up of one 2006-12-18T22:22:33-05:00 http://75.150.148.189/free-essay/In-Favor-of-Increased-Cloning-Research-32037.aspx Research on the Human Genome Project A genome is the complete collection of an organism’s genetic material. The human genome is composed of about 50,000 to 100,000 genes located on the 23 pairs of chromosomes in a human cell. A single human chromosome may contain more than 250 million DNA base pairs, and it is estimated that the entire human genome consists of about 3 billion base pairs. Now knowledgeable of the genome, one can fix his or her attention on the Human Genome Project. The goal of which is to gain a basic understanding of the entire genetic blueprint of a human being. This genetic information is found in each cell of the body, encoded in the chemical deoxyribonucleic acid (DNA). The project is intended to identify all the genes in the nucleus of a human cell; to establish, by a process known as mapping, where those genes are located on the chromosomes in the nucleus; and to determine, by a process known as sequencing, the genetic information encoded by the order of the DNA’s chemical subunits. The ultimate goal of genomic mapping and sequencing is to associate specific human traits and inherited diseases with particular genes at precise locations on the chromosomes. The successful completion of the genome project will provide an unparalleled understanding of the fundamental organization of human genes and chromosomes. It promises to revolutionize both therapeutic and preventive medicine by providing insights into the basic biochemical processes that underlie many human diseases. The idea of undertaking a coordinated study of the human genome arose from a series of scientific conferences held between 1985 and 1987. The Human Genome Project began in earnest in the United States in 1990 with the expansion of funding from the National Institutes of Health (NIH) and the Department of Energy (DOE). One of the first directors of the U.S. program was American biochemist James Watson, who in 1962 shared the Nobel Prize in physiology or medicine with British biophysicists Francis Crick and Maurice Wilkins for the discovery of the structure of DNA. Many nations have official human-genome research programs as part of this informal collaboration, including France, Germany, Japan, the United Kingdom, and other members of the European Union. In separate projects intended to speed up the mapping and sequencing process, several private companies, including Celera Genomics, are also sequencing the human genome. The National Human Genome 2006-12-18T22:10:47-05:00 http://75.150.148.189/free-essay/Research-on-the-Human-Genome-Project-32032.aspx (1) Coronary heart disease is a disease of the arteries supplying blood to the muscle forming the walls of the heart. The blockage of a coronary artery is called coronary thrombosis or heart attack, causing extreme and gripping chest pains. If a coronary artery is blocked, part of the heart muscle does not receive any blood. The muscle cells receive no oxygen, they cannot respire and therefore they die. The size of the heart attack depends upon the size and position of the coronary artery blocked. If a small branch of an artery is blocked, only a small amount of muscle dies causing a small heart attack. If a large artery is blocked, the whole heart may stop contracting, resulting in a cardiac arrest. (1)) (1)Atherosclerosis is a main cause of CHD. This is the progressive blocking of arteries with atheroma. These are deposits of cholesterol and fibrous tissue which narrow the arteries, reducing blood flow and making the artery walls less elastic, and therefore roughening their inner surface. There are a number of factors that can affect Atherosclerosis.((4) Lack of physical inactivity is a common risk factor. 7 out of 10 adults in the UK do not take enough regular physical activity. (4)) Physical activity also raises HDL cholesterol levels which with regular physical activity lowers the damaging LDL levels. Regular exercise helps to prevent blood clotting by providing sufficient blood flow to remove and stop the build up of atheroma, therefore preventing coronary thrombosis. (4)) Preventing the build up of atheroma can be prevented by physical exercise as this raises the amount of high-density lipoprotein cholesterol in our arteries. However it is the fact that excess cholesterol is present in our arteries that results in a dangerous amount of atheroma forming in the coronary artery and this excess comes from our diet. ((1) Some cholesterol is essential for our bodies to function as they are needed in cell membranes, however the level of cholesterol entering our bodies through diet is a major factor affecting coronary heart disease. The level of LDL cholesterol in the blood tends to rise, and HDL falls, with the amount of saturated fats and ((5) triglycerides in a diet. (1+5)) ((4) Atheroma develops when LDL cholesterol is oxidised and is taken up by cells in the coronary artery walls where the narrowing process begins eventually resulting in 2006-12-10T19:04:03-05:00 http://75.150.148.189/free-essay/The-Factors-that-Affect-Coronary-Heart-Disease-31969.aspx Evolution Of The Nervous System Through Nine Animal Phylum The only multi-cellular animals without a nervous system are sponges. They do not have any nerve cells or sensory cells. Despite this, touch or pressure to the outside of a sponge will cause a local contraction of its body. Cnidarians The jellyfish and most all other forms of cnidarians, such as the hydra and sea anemone, are characterized by a nerve net. A nerve net is a series of interconnected nerve cells that conduct impulses around the jellyfish’s entire body. The strength of the jellyfish’s response is proportional to the strength by which the jellyfish is being stimulated. So, in other words, the stronger the stimulus is the stronger the reaction will be. Platyhelminthes The nervous system of the planaria, similar to that of many platyhelminthes, is only a step above the simple nerve net of the Cnidarians. In addition to the nerve net, the platyhelminthes have long nerve cords that connect the different sections of nerve nets. All of the nerve cords come together at a location near the head called the cerebral ganglion. The central nervous system has been described as ladder-like because of the nerves connecting the cords. Nematoda The nematoda have a simple nervous system. It consists of a ring of nervous tissue around the pharynx that gives rise to dorsal and ventral nerve cords running the length of the body. The dorsal nerve cord runs along the top of the intestine and the lateral nerve cord runs to the left of the intestine. When the nerve cords are stimulated they cause the longitudinal muscle, which runs all along the outside of the body, to contract. Annelida The brain of most annelids is relatively simple in structure. In some, the brain is divided into a forebrain, midbrain, and hindbrain. Sensory nerves leave the brain and run forward into the prostomium and first segment. A single pair of circumesophageal connectives leaves the brain, surround the anterior gut, and connect with the ventral nerve cord. The most primitive annelids have a pair of ventral nerve cords joined by transverse connectives; the most advanced forms have the cords fused to form a single cord. A ganglionic swelling of the cord is found in each body segment. Two to five pairs of lateral nerves leave each ganglion to innervate the body wall of that segment. 2006-12-08T03:19:14-05:00 http://75.150.148.189/free-essay/Evolution-Of-The-Nervous-System-Through-Nine-Animal-Phylum-31952.aspx Learning about Nutrition We just spent the last couple of weeks learning about nutrition. We learned all about the proper foods to eat, and the amounts of each food group and nutrient we need to stay healthy. We learned about our own eating habits by recording what we ate for three days and by applying what we learned in class I was able to examine my good and bad eating habits. I now know what I can do to improve myself, and achieve optimum health. After reviewing my three-day eating habits, I noticed I don’t eat the recommended 2-4 servings of fruit or the 3-5 servings of veggies. On the bright side to our recording I found that I get plenty dairy, and grains servings, sometimes even 3 servings more then the recommended, this is good because I will have stronger bones, and more energy. If I learn to eat more fruits and veggies, I will become an even more healthy person. The one category I was really disappointed in was the fat percentage. I’m recommended to have 20% fat every day. On the average I had 39% fat, which is 19%over the recommended amount. This really surprised me because I felt I didn’t eat that much fat. In order to improve this bad habit I will try and eat less fatty foods and in their place eat more fruits and veggies, which is what I need. Doing this will greatly improve my health. At the present time I am trying to maintain my present weight. I have a strenuous exercise schedule, exercises at least six times every week for at least an hour and a half. For my height of 5’8’’ and my exercise level it is recommended that I consume 2400 calories a day. My average was 2465, which is only 65 calories over the recommended amount. I was very pleased to see that I was so close to the right amount, although I’m over just a little bit I don’t think it will harm me in the long run, so I plan on eating the same. After reviewing my results I feel that I need to alter what I eat. I found that I don’t get enough protein, vitamins, and minerals. On the other hand I found that I do get enough 2006-12-04T20:55:05-05:00 http://75.150.148.189/free-essay/Learning-about-Nutrition-31861.aspx Implications of Inheriting your Human Genes Have you notice that some people are just not born with a good physical appearance or good health? This is because some people are not born with the immaculate genes that those fortunate people are born with. The great Aristotle once said, “Those who are sprung from better ancestors are likely to be better men, for nobility is excellence of family.” (Dobzhansky 8) Genetics determine many birth defects, disease, and cancer as well Our surrounding environment, which could include pollutants contribute to mutating genes which could also lead to disease or other health problems. Genetics isn’t simply the study of the inheritance of traits but also with how humans live, grow, and develop. (Bornstein 12) Although genes predetermine and limit someone’s health, exercise can enhance a person’s health and physical appearance. Our genes influence a person’s physical appearance and as well as health. Our growth, development, health, and appearance is effected by our hereditary genes. Hereditary genes are genes which are inherited by one’s children. Certain physical characteristics undoubtedly run in the family. Even a newborn baby is declared by admiring relatives to have “Dad’s eyes” and “Mom’s mouth” or other particular features that are somehow different from the average yet specific to the parents. All of these and many other characteristics are the results of heredity and of genetic programming involving both parents. (Marshall 7) Everyone shares genes with their relatives, and have half of each of our parents genes. Our genes make us all unique, making no one the same. No one has exactly the same genes, even twin have microscopic differences. Some people are born with the genes which inevitably make them obese. No matter how healthy they eat or how much they contribute to exercising, good health is virtually impossible. (Marshall 33) Although some people are stricken to bad health, our environment shapes who you finally become from the moment of conception onward. Just as a twig is bent, environment can change the first impression or appearance of something or someone all the same. For example, someone’s skin color can be strongly changed by outdoor life or can be lightened with no exposure to outdoors. You can not change your genes but you can modify it with your 2006-11-17T02:47:15-05:00 http://75.150.148.189/free-essay/Implications-of-Inheriting-your-Human-Genes-31806.aspx History of the Human Genome Project The human genome project was started in with its conception in the mid 1980’s. The United States government was responsible for all the formal planning and its development. The most outstanding goal for the project is to determine the entire nucleotide sequence of the human DNA. This consists of an estimated 50,00 to 100,000genes within one human genome. The process of the entire has required developing new technology in the field of genetics. From the inception of the project it was clear that new discoveries that the project would bring new breakthroughs and new problems. There are new and interesting controversies with the human genome project. The most important to me is the choice of the possibility of choosing the best of your genes to make your child the greatest it can be. Some of the concerns with this issue are having all these super babies around is that our world will no longer be natural and more man made than in the hands of god to choose the way our children look, think, and how successful they are in life. Also with this the life expectancy of these new super babies will increase because they will have the best of everything form there parents and will not have any chance of ding young form a natural cause such as heart disease or cancer. My opinion on this very concerning issue is that only a select few should be able to choose e there children’s genetic information. The people who should be able to choose their kids genetic information is the people who can not have a normal child unless their genetic information is change in their kid. The reasoning behind this is that I believe the every married couple should be able to have a normal child because the greatest thing in life I think is seeing your perfect little child grow up to became a young man or woman. On the other hand I think people who now that now they can have a normal should be outlawed to use this information to make a super baby and let god do his work and bring them there little bundle of joy. The worst thing with being able to choose your child’s genetic makeup is being able to now everything your child will do in his lifetime and that ruins the whole joy of 2006-11-17T02:38:15-05:00 http://75.150.148.189/free-essay/History-of-the-Human-Genome-Project-31801.aspx Informational Essay on Black Leopards In this melanistic form the cats are more difficult to separate, however the jaguars large head and stocky forelimbs are often a good way to differentiate between the two cats. In the wild, identification would not be an issue as the cats inhabit different continents - the jaguar is the only member of the panthera family to be found in the Americas and its is by far the biggest cat on the continent. The Jaguars range, which once spanned from the southern states of the USA down to the tip of South America, now centers on the north and central parts of the South American continent. The jaguar is predominantly a forest dweller with the highest population densities centering on the lowland rain forests of the Amazon Basin - dry woodland and grassland also serve as suitable terrain, although the cat is rarely found in areas above 8000 feet. During the peak of its decline in the sixties and seventies, around 18,000 jaguars were killed every year for there much sought after coat. Due to environmental pressure the fashion for animal furs has declined, but the jaguar is still hunted. Today the major threat comes from deforestation which is drastically affecting the jaguars prey base as well as fragmenting the cats population into more isolated pockets. It is estimated that there are now only around 15,000 jaguars left in the wild and conservation is centering on the establishment of protected ‘National Park’ areas which may serve to reduce the decline of the jaguars natural habitat. In Belize, the government, aided by the WWF, have set aside 150 square miles of rain forest in the Cockscomb Basin Wildlife Preserve, which currently provides a protected environment for around 200 jaguars, the largest concentration of the wild cats species in the world. The WWF are also providing aid to protect some of the remaining rain forests areas of South America, which provide a refuge for the majority of the remaining jaguar population .During the peak of its decline in the sixties and seventies, around 18,000 jaguars were killed every year for there much sought after coat. Due to environmental pressure the fashion for animal furs has declined, but the jaguar is still hunted. Today the major threat comes from deforestation which is drastically affecting the jaguars prey base as well as fragmenting the cats population into more isolated 2006-11-17T01:19:10-05:00 http://75.150.148.189/free-essay/Informational-Essay-on-Black-Leopards-31769.aspx The Dangers and Reality of Acid Rain Acidity is measured using a pH scale, with the number 7 being neutral. A substance with a pH value of less than 7 is acidic, while one of a value greater than 7 is basic. A substance with a pH of 6 is 10 times more acidic than another with a pH of 7. Usually the pH of 5.6 has been used as the baseline in identifying acid rain, although there has been much debate over the acceptance of this value. Interestingly enough, a pH of 5.6 is the pH value of carbon dioxide in equilibrium with distilled water. Hence, acid ran is defined as any rainfall that has an acidity level beyond what is expected in non-polluted rainfall. In essence, any precipitation that has a pH value of less than 5.6 is considered to be acid precipitation. One of the main causes of acid rain is sulphur dioxide. Natural sources which emit this gas are volcanoes, sea spray , rotting vegetation and plankton. However, the burning of fossil fuels, such as coal and oil, are largely to be blamed for approximately half of the emissions of this gas in the world. When sulphur dioxide reaches the atmosphere, it oxidizes first . It then becomes sulphuric acid as it joins with hydrogen atoms in the air and falls back down to earth. Oxidation occurs the most in clouds and especially in heavily polluted air where other compounds such as ammonia and ozone help to catalyze the reaction, converting more sulphur dioxide to sulphuric acid. However, not all of the sulphur dioxide is converted to sulphuric acid. In fact, a substantial amount can float up into the atmosphere, move over to another area and return to earth unconverted. Nitric oxide and nitric dioxide are also components of acid rain. The sources of these components are mainly from power stations and exhaust fumes. One of the most serious impacts of acid precipitation is on forests and soils. Great damage is done when sulphuric acid falls onto the earth as rain. Nutrients present in the soils are washed away. Aluminium also present in the soil is freed and this toxic element can be absorbed by the roots of trees. Thus, the trees are starved to death as they are deprived of their vital nutrients such as calcium and magnesium. Research has been made where 2006-11-15T22:55:42-05:00 http://75.150.148.189/free-essay/The-Dangers-and-Reality-of-Acid-Rain-31757.aspx The Circulatory System Circulatory System is the combined function of the heart, blood, and blood vessels to transport oxygen and nutrients to organs and tissues throughout the body and carry away waste products. The circulatory system increases the flow of blood to meet increased energy demands during exercise and regulates body temperature. Also, when foreign substances or organisms invade the body, the circulatory system quickly sends disease-fighting elements of the immune system, such as white blood cells and antibodies, to places under attack. In the case of injury or bleeding, the circulatory system sends clotting cells and proteins to the affected site, which quickly stop bleeding and promote healing. The heart, blood, and blood vessels are the three main elements that make up the circulatory system. The heart is the engine of the circulatory system. It is divided into four chambers, the right atrium, the right ventricle, the left atrium, and the left ventricle. The walls of these chambers are made of a muscle called myocardium, which contracts to pump blood. The pumping action of the heart occurs in two stages for each heartbeat. Diastole, when the heart is at rest, and systole, when the heart contracts to pump deoxygenated blood toward the lungs and oxygenated blood to the body. There are typically about 60 to 90 beats per minute. If the heart stops pumping, death usually occurs within four to five minutes. Blood consists of three types of cells, red blood cells that carry oxygen, disease-fighting white blood cells, and blood-clotting platelets, which are all carried through plasma. Plasma is yellowish and consists of water, salts, proteins, vitamins, minerals, hormones, dissolved gases, and fats. Three types of blood vessels make a network of tubes throughout the body. Arteries carry blood away from the heart, and veins carry it toward the heart. Capillaries are tiny links between the arteries and the veins where oxygen and nutrients spread to body tissues. The inner layer of blood vessels is lined with cells that create a smooth passage for the transfer of blood. This inner layer is surrounded by connective tissue and smooth muscle that help the blood vessel to expand or contract. Blood vessels expand during exercise to meet the increased demand for blood and to cool the body. Blood vessels contract after an injury to reduce bleeding and also to conserve body heat. Arteries have thicker walls than veins 2006-10-29T22:27:18-04:00 http://75.150.148.189/free-essay/The-Circulatory-System-31623.aspx Biological and Historical Information on the Ebola Virus The Ebola virus belongs to the family Filoviridae. The Ebola virus is characterized by massive bleeding and destruction of internal tissues. The virus is named after the Ebola river in the Democratic Republic of Congo, Africa where the virus was first found. Three types of the Ebola virus have been found. They are named after the places in which they were discovered. Ebola –Zaire, Ebola-Sudan, Ebola-Tai forest. The strain Ebola –Zaire is the most deadly of the three. The Ebola viruses are mainly found in Central Africa. Recent outbreaks in humans have been discovered in areas where there aren’t enough medical supplies or care. This is a problem because the virus strikes in remote areas where access to laboratories is very limited making diagnosing the virus difficult. The first outbreak of the virus was identified 1976 in Zaire and Sudan. In Sudan 284 people were infected and 117 died. In Zaire there were 318 people infected and of those infected only 38 survived. In 1989 a fourth strain was discovered in a quarantine laboratory in Reston ,Virginia that held hundreds of imported Philippine monkeys. Four lab technicians were infected but none of them became ill, though all the monkeys died. The Ebola-Reston was found not to cause disease in humans. In 1995 a large epidemic occurred in Kikwit,Zaire. There were 315 cases and 244 fatalities. Except for a few small out breaks the Ebola virus infections were not reported again until the fall of 2000 in Uganda. The Ebola virus is transmitted by direct contact of the blood, secretions, organs and semen of infected persons. Handling an ill or dead infected chimpanzee was also proven to be a way of transmission of the disease. Infections frequently occur in hospital care workers or family members who care for a person infected with the Ebola virus. Reusing needles is another way of spreading the virus. In developing countries like Sudan and Zaire reusing needles is very common because the health care system is under financed. The Ebola virus can be spread through sexual contact. Patients who have recovered from the virus aren’t likely to spread the infection but, the virus still may be present in the genital secretions shortly after their recovery ,therefore making it possible to spread the disease through sexual contact. People at risk of the Ebola virus are persons traveling to areas 2006-10-29T22:23:51-04:00 http://75.150.148.189/free-essay/Biological-and-Historical-Information-on-the-Ebola-Virus-31621.aspx Natural Selection and Diseases Cystic fibrosis, Tay-Sachs, and hypertension are three very different, yet deadly diseases. The question arises how these diseases have survived for so long. Three articles attempt to uncover the mystery behind these diseases. It has been found that there were benefits to each of these diseases, which allowed the allele to remain in the community for such a long period of time. Natural selection plays a large part in the success of these conditions. First, cystic fibrosis has been found to be prevalent in Caucasians. It is the most fatal genetic disorder among this group. It is difficult to understand how this disease has survived for 52,000 years, especially before the development of modern medicine. The disease generally killed people before they could reproduce. In a normal situation, natural selection should have gotten rid of this defective gene; however, it did not. This suggests that cystic fibrosis may have some usefulness in society that we were unaware of until now. The author of this article suggests that those who carry the cystic fibrosis gene are protected against diarrhea. In order to understand this, it is important to know how cystic fibrosis affects the body. The gene for cystic fibrosis codes for a protein that forms channels in cell membranes. These channels funnel chloride ions out of a cell, make the surroundings saltier, and draw water out of the cell by osmosis. The fluid is useful in getting rid of unwanted debris in the lungs. For sweat glands, these channels recycle salt out of the glands and back to the skin before the salt is lost. People with cystic fibrosis have excessively salty sweat and they lack functional chloride channels. Another symptom of cystic fibrosis is thick, sticky, dry mucus clogging the lungs because the cells are not ejecting water. Medical geneticist Xavier Estivill concluded from experiments with mice that mutations of cystic fibrosis offer some resistance to cholera and other diarrhea-inducing bacteria. Persons who are heterozygous for this gene will not have all the characteristics of an individual with cystic fibrosis, but they will have one defective gene coding for chloride channels. When the bacteria causing cholera gets into the small intestines, it releases a toxin that causes the cells to permanently open the chloride channels in 2006-10-27T19:48:15-04:00 http://75.150.148.189/free-essay/Natural-Selection-and-Diseases-31572.aspx Global warming is an increase in the earth's temperature due to fossil fuels, industry, and agricultural processes caused by human, natural, and other gas emissions. This results in an increased emission of greenhouse gases. Short-wave solar radiation sinks into the Earth's atmosphere and warms its surface; while long wave infrared radiation emitted by earth's surface is absorbed, and then re-emitted by trace gases. Climate changes occur in our earth's atmosphere due to a buildup of greenhouse gases. Greenhouse gases can occur naturally as well as a result of human activities. Problems can occur when higher concentrations of greenhouse gases are present in our atmosphere because they have enhanced our earth's heat trapping capability. There are many misconceptions about global warming. Some believe that pollution causes global warming, but the fact is global warming is the result of burning fossil fuels, coal, and oil that release carbon dioxide. Another misconception is nuclear power causes climate change. Nuclear power actually reduces emissions of carbon dioxide when used in place of coal. Some believe that global warming means that it will become warmer all over. The name is misleading because in some places, it will actually become colder. The majority of scientists believe global warming is a process underway and that it is human-induced. The greenhouse gases are carbon dioxide, methane, and nitrous oxide. These gases occur naturally. The Earth uses those gases to warm its surface. Carbon dioxide is released into the atmosphere when solid waste, fossil fuels, wood, and wood products are burned. Each greenhouse gas absorbs heat differently. If natural gases did not occur, the temperatures would be 91.4 degrees cooler than the current temperatures. These gases trap heat and cause the greenhouse effect, rising global temperatures. Human activities add to the levels of these gasses, causing more problems. The burning of solid waste, fossil fuels, and wood products are major causes. Automobiles, heat from homes and businesses, and factories are responsible for about 80% of today's carbon dioxide emissions, 25% of methane, and 20% of the nitrous oxide emissions. The increase in agriculture, deforestation, landfills, industrial production, and mining contribute a significant share of emissions too. The gases released into the atmosphere are tracked by emission inventories. An emission inventory counts the amount of air pollutants discharged into the atmosphere. These 2006-10-26T02:16:45-04:00 http://75.150.148.189/free-essay/Global-Warming-31550.aspx AP Laboratory : Enzyme Catalysis Purpose - The purpose of this lab is to use a chemical titration to measure and them calculate the rate of conversion of hydrogen peroxide (H2O2) to water and oxygen gas using the enzyme catalase. Hypothesis - The rate of enzymatically-catalyzed reactions can be determined by taking time reactions at different time intervals. When the rates are plotted on a graph, the rate of the reaction is the slope of the linear portion of the curve. To determine a rate, any two points on the straight-line portion of the curve is picked out. Divided the difference in the amount of product formed between these two points by the difference in time between them. The result will be the rate of the reaction. I believe that the reactions rate will be that highest during the first interval (0-10 seconds) because there are larger amounts of substrate molecules than enzyme molecules, but as times increase the lower the reaction rate because there will be more product molecules as result of the chemical reactions between the enzyme and the substrate. Materials: •ring stand •double clamp •2 burettes •beakers •test tube •1.5% hydrogen peroxide (H2O2) •distilled water •liver •potassium permanganate (KMnO4) •graduate cylinders •1.0% sulfuric acid (H2SO4) Procedure: See handout Observations: See handout Analysis - My hypothesis proved to be correct. The reaction rate was the highest during the intervals of (0-10 seconds) and also at the beginning of 10-30 seconds because there is a large amount of substrate molecules in comparison to the number of enzyme molecules and there will be a maximal number of collisions between the enzymes and the substrate. As the number in seconds increased the reaction rate decreased. The lowest reaction rate was during the last interval (120-180 seconds). As the number of substrate molecules decreased and the number of product molecules (O2) increases the number of collisions between the substrate decreases. Eventually, the enzyme will break all of the substrate down, since 02 escapes from the system. Conclusion - In this lab catalase is the enzyme. It will react with hydrogen peroxide (H2O2), the substate. The products formed should be water and oxygen. H2O2 --catalase--> H2O + O2 In Exercise 2A the bubbles coming form the reaction mixture are O2, which results from the breakdown of H2O2. By capturing the evolved gas in a test tube and inserting a glowing splint one could show that the gas evolved 2006-08-29T15:32:33-04:00 http://75.150.148.189/free-essay/AP-Laboratory-Enzyme-Catalysis-31372.aspx History of the Human Genome Project The Human Genome Project (HGP) is an international research effort to decipher the entire human genome and understand the unique hereditary instructions that each person possesses. The HGP is a jointly funded project by the U.S. Department of Energy (DOE) and the National Institutes of Health (NIH) with additional research done by the National (NHGRI). The project, launched in 1990, was originally planned to last 15 years, but rapid advances in technology have accelerated the expected completion date to 2003. The Joint Genome Institute (JGI), established in 1997, is one of the largest publicly funded human genome sequencing centers in the world and contributes greatly to the HGP. The Wellcome Trust in the United Kingdom also contributes substantial investments to the HGP. The roots of the HGP can be traced back to the atomic bomb era that began during World War II. Descendants of bomb survivors harbor DNA mutations as a result of severe radiation exposure. These mutations were passed to their descendents who developed horrible diseases and malformations. The DOE’s role in the HGP arose to study the genetic and health effects or potential health risks of radiation and chemical by-products of energy production. Scientists realize the best way to study and treat these effects were to directly study DNA, so blood samples were collected and stored for future DNA analysis. At a joint DOE and International Commission on Protection against Environmental Mutagens and Carcinogens (ICPAEMC) in 1984, the question was asked, “Can we, and should we, sequence the human genome?” After lengthy debates, scientists eventually decided to do it. In 1986, the DOE announced its Human Genome Initiative to decipher the human genetic script. The HGP will transform both biology and medicine. The goals of the HGP are to identify the approximate 80 to 100,000 genes in human DNA and determine the sequences of the approximately 3.2-billion chemical bases that make up human DNA. This information will be stored in computer databases while data analysis tools will be developed to apply this information to human biology and medicine. Results of the HGP are hoped to transform the treatment of symptoms in molecular medicine to address the deepest causes of disease at their molecular foundations in their earliest stages. Gene therapy will soon be “fixing” genetic errors before they result in disease. 2006-08-29T15:29:27-04:00 http://75.150.148.189/free-essay/History-of-the-Human-Genome-Project-31370.aspx Scientific Experiments Regarding Evolution Science has proven that evolution is the key to our adaptation patterns. Over millions of years humans, birds, reptiles, and fish have evolved to survive in their environments. This can be found in the simplest life forms as well as the most complicated life forms. Examples of this can be found in cavefish losing their eyes from nonuse and humans losing large amounts of body hair from living in warmer dwellings. Scientist have shown exactly how fast the evolutionary process can be with an experiment held on salmon in the late 1930’s. An experiment held by biologist in the Northwest has shown how salmon, which were introduced to Lake Washington in 1937, have evolved incredibly over thirteen generations. Lake Washington basically has two environments: the beach and the river environments. The male salmon that moved to the river became more streamlined so they could swim up strong river currents better, while the females grew 10% bigger than their sister, the lake females. The females gained size aids in their nest building abilities. Both river and lake females make their nest by slamming their bodies into the lake or riverbed which leaves a nice trench to deposit their eggs into. After the eggs have been laid, they swim upstream to stir up gravel, which will drift over the eggs to form a protective blanket over them. As you can see, the size advantage of the river salmon allows her to dig deeper trenches that will protect her eggs from the stronger current and the flooding river. The lake males grew a larger hump in front of their dorsal fin. Their gained size slows them down in the river, but allows them to become better sexual competitors in the lakes. The evolution between these salmon has caused their DNA to become genetically different. These differences in their DNA cause both females and males to look completely different. These physical differences are probably what is causing these fish not to interbreed. The physical advantages of in their own environments allow them to mate and reproduce with fish of their own kind. Evolution can be found in all forms of life. Survival of the fittest is Mother Nature’s way of weeding out the weak. So if a species is weak and can’t adapt, they slowly die off. 2006-08-27T23:57:00-04:00 http://75.150.148.189/free-essay/Scientific-Experiments-Regarding-Evolution-31353.aspx Introduction to Enzyme Kinetics The purpose of this experiment is to measure the rates of reaction of the enzyme Alkaline Phosphatase with the substrate p-nitrophenol phosphate under varying conditions. The concentration of both substrate and enzyme were diluted and the inhibitor vanadate was utilized to determine whether or not the reaction is substrate or enzyme dependent and to see what type of inhibition vanadate was involved. A class of proteins called enzymes catalyzes almost every chemical reaction in a cell. Enzymes increase the rates of reaction for those reactions, which are already energetically favorable, by lowering the activation energy. Enzymatic reactions differ from other chemical reactions, by having a higher reaction rates, greater specificity, and high capacity for regulation. Quite often, the rate of an enzymatically catalyzed reaction is 106-1010 times that of an uncatalyzed reaction under similar conditions. Enzymes are most effective under the optimal conditions of a cell, in which the cells aqueous environment is 37° C, and has a pH between 6.5-7.5. Enzyme kinetics, the rate of reaction, and how this rate is influenced by different factors are directly correlated to the path followed by the reaction. For example, the enzyme-substrate reaction rate can be affected when there is a competitive inhibitor is involved. In the reaction, the competitive inhibitor competes with the substrate for the enzyme’s active site. This results in a lower reaction rate of the enzyme-substrate. On the other hand, noncompetitive inhibitors do not compete with the substrate for the active site and will not affect the affinity of the enzyme for its substrate, however, it will affect the maximum velocity of the reaction. The catalytic action of an enzyme on a given substrate can be described by two parameters: Km (the Michaelis constant), which measures the affinity of an enzyme for its substrate, and Vmax, which measures the maximal velocity of the reaction at saturating substrate concentration. From the Michaelis-Menton complex: E + S « ES « E + P Where E is the enzyme, S is the substrate, and P is the product. The rate of product formation V can be dertermined by the equation below. V= Vmax [S]/[S] + Km From this equation, we can predict that when the V is independent from [S] the reaction would be zero order, whereas when V is dependent on [S], the reaction is first 2006-08-27T23:45:32-04:00 http://75.150.148.189/free-essay/Introduction-to-Enzyme-Kinetics-31346.aspx Differences Among Deciduous and Coniferous Trees As stated by the General Ecology book, competition is the interaction between two species over a limiting resource that negatively affects one or both of their population growth rates. Intraspecific competition is the competition between members of the same species. This can include competition for light, water, nutrients, and space. A tree's life traits are also of great importance. They can effect the distribution, abundance and density found in an area. Coniferous trees are those which keep their leaves throughout the winter. They have small leaves called needles that are coated with wax to prevent water loss, and are soaked in resin which helps the needles withstand freezing. The needle shape is and asset in winter because it offers no resistance to wind. As a result of these adaptations conifers can grow where soils are shallow and poor, and where moisture is low. Another advantage of conifers is that they can hold their needles all winter and therefore, they can start photosynthesis early in spring as soon as the sun gets warmer and the ice melts. The coniferous tree used in this experiment was the white spruce. The white spruce tree grows in forests with well-drained soils. Although the white spruce needs well-aerated water to grow efficiently it can survive in various moisture conditions and will grow on dry soil if it is fertile. The white spruce prefers sun but can also live in some shade. It is a hardy tree, withstanding wind, heat, cold, drought and crowding (Earl Rook 1998). This permits it to have a random distribution and high density. Since it can withstand such variety, abundance would be favorably strong. Deciduous trees are those that shed their needles in the fall and remain dormant in the winter so that they can survive until the spring. Their leaves are wide and long which allows for maximum photosynthesis during their short growing season. This adaptation enables them to be better food producers than conifers. The deciduous tree used in this experiment was the poplar. Its canopy (highest level of foliage in a forest) typically allows more sunlight to reach the forest floor than do conifers. In addition to providing key habitat for wildlife, some may act as a ‘nurse crop’ for shade-tolerant species that do not become established in full sunlight (eg.conifers) (Douglas Johnson 1999) The poplar is found in a variety of 2006-08-25T20:49:40-04:00 http://75.150.148.189/free-essay/Differences-Among-Deciduous-and-Coniferous-Trees-31282.aspx Antibiotic Resistant Bacteria Bacteria’s are one-celled organisms that were discovered in 1676 by Anthony Van Leeuwenhoek. Many people like to define bacteria as a germ, but in reality germs are a form of bacteria. Most bacteria are not harmful to one’s body but helpful in ways no one expects. (Lietz 6) For example bacteria located in soil that is used to grow food by turning dead animals and plants into the rich, dark topsoil. (Leitz 7) They also make shelter for humans and animals. Bacteria are removed from ones teeth and body after brushing and bathing daily. (Leitz 59) It is always completely surrounding everyone daily and no matter where you go it will always be with you at all times. (Leitz 10) Dr. Alexander Fleming discovered penicillin in 1928 and this penicillin was made of mold and killed many types of germs and was later tested on rabbits and resulted in no harm to the rabbit. The problem was that no one was able to make large quantities of it so it was not used very often. (Leitz 45) After ten years of consistent growing of the penicillin it was finally able to be used on a few dying patients. (Leitz 46-47) In late 1942 penicillin actually began to sell and save lives all over. This form of mold known as penicillin is a form of an antibiotic. Antibiotics are a bacteria fighter that made from mold and fungi. It is a drug that became very common and worked against many germs. (Leitz 49) Penicillin back in the 1940’s cured many infections such as staphylococcus, pneumococcus and entercococcus, tuberculosis, syphilis, and gonorrhea. As time passed on there were many new antibiotics being made and taking care of new infections or diseases, so antibiotic-resistant bacteria was never suspected and would have been the last thought to scientist who were curing people every day. (Hickling 1) Since then till the present there have been many different antibiotics found and they are helping people fight bacteria everyday. There are different types of drugs/antibiotic’s that help different types of diseases and bacteria’s. Infections of bacterial are becoming just as common as any other disease killing the population. This has become a major health threat to the population and will eventually become the biggest if something 2006-08-09T12:20:06-04:00 http://75.150.148.189/free-essay/Antibiotic-Resistant-Bacteria-31186.aspx Protozoan & Vorticella Organisism Protozoa, collective name for animal-like, single-celled organisms, some of which may form colonies. In the classification followed in this essay the protozoa are placed in the kingdom Protista with other single-celled organisms that have membrane-enclosed nuclei. Protozoa have little or no differentiation into tissue systems. Several phyla are commonly recognized. They include flagellated Zoomastigina, many species of which live as parasites in plants and animals; the amoeboid Sarcodina, which includes the Foraminifera, and Radiolaria both important components of the plankton; ciliated Ciliophora, many with specialized structures suggesting the mouth and anus of higher organisms; Cnidosporidia, parasites of invertebrates, fish, and a few 2006-08-06T21:54:30-04:00 http://75.150.148.189/free-essay/Protozoan-amp-Vorticella-Organisism-31086.aspx Essay on Important Cell Components Being one of the most important components of a cell, the plasma membrane, or cell membrane plays a huge role in regulating how things get in and out of cells. The plasma membrane’s unique structure enables it to let only certain molecules pass through the cell. This ability is called selective permeability. Most of the plasma membrane in most cells is made up of a phospholipid bilayer with proteins either embedded into it or sticking out from either side of the membrane. The heads of the phospholipids absorb water from the extracellular environment while the tails of the phospholipids repels it. This system helps the membrane regulate the flow of water in and out of the cell, and is also responsible for letting in hydrophobic or water repelling molecules into and out of the cell as well. Molecules may enter the cell via two main kinds of transport: active and passive. Passive transport is the movement of molecules through the cell membrane that requires no energy. The molecules passing through the membrane move from the area of the higher concentration to the area with a lower concentration. In other words, the molecules move along the gradient and therefore do not need energy to help them move through the membrane. Diffusion is another word for passive transport and is categorized by two ways: facilitated and simple. In simple diffusion, the molecules are either hydrophilic or small enough to pass through the phospholipid bilayer without any assistance. In facilitated diffusion, proteins embedded in the cell membrane, provide a doorway for particular solutes to go through. Even though the proteins move in order to make openings for solutes, this process does not use any energy. Water is crucial for the survival of cells. Water is able to diffuse through the membrane by a method of passive transport called osmosis. Osmoregulation is the control of the water balance in cells. The amount of water in and out of cells has a great effect on the concentration gradient inside and outside cells. When there is more water inside the cell and more solutes outside the cell, the cell is hypotonic to the extracellular fluid. In other words, the cell is in a hypertonic solution. As a result of this, more water molecules leave the cell 2006-08-06T20:36:21-04:00 http://75.150.148.189/free-essay/Essay-on-Important-Cell-Components-31076.aspx The Inland Bearded Dragon (Pogona Vitticeps) The bearded dragon (also called the yellow-headed bearded dragon) native to inland or central Australia is a very versatile lizard. In Australia these little guys can be found living in the arid, rocky, semi-desert regions, arid woodlands or scrub. They are frequently found basking in the morning and afternoon sun or rocks, logs and even fence posts. Their bulky body and basking allows them to store heat and operate at lower temperatures than other lizards. Bearded dragons can also survive very high temperatures for several hours since they can regulate there body temperature by evaporation. They are generally very brave individuals and are not generally bothered by humans, which is one of the reasons they have become popular pets. There basic color varies from shades of brown and reddish-brown, gray and bright orange. The adult males have a dark beard, which becomes black during courtship and breading. They average18” to 24” from nose to tail and there average weight is between 10 – 18 ounces. The bearded dragons head is somewhat arrow shaped as opposed to the slightly rounded head of the horned toad native to the American Southwest. It’s body is somewhat flat and is liberally covered with sharp “appearing” spikes. The bearded dragon’s tail only makes up about half of its length. Females are generally stockier though somewhat shorter than the males of the species. The scales along the throat and side of the head have evolved into spiny points they also have these pointy scales along the sides of their bodies. They received the name “bearded” from their flared out throat that it uses to help scare off potential predators. While they flare out there throat they open their gaping mouth, which is lined with yellowish-orange coloring to help add to there threatening appearance and can stand on there hind legs. The bearded dragons adapt so well to living in captivity this behavior is rarely observed. The most one is likely to see is it flattens its body and possibly flare its “beard”. The bearded dragons have the ability to change shades from dark to light, which aids them in regulating their body temperatures. They can also change colors depending on emotional state and for concealment. When injured, sick or dying the bearded dragon becomes black on its 2006-08-05T10:29:23-04:00 http://75.150.148.189/free-essay/The-Inland-Bearded-Dragon-Pogona-Vitticeps-31014.aspx Avian Influenza or better known as the ‘Bird Flu’ is an extremely infectious disease caused by a type A strain of the influenza virus. First identified in Italy a mere one hundred years ago, wild bird populations carry these normally non-lethal flu diseases worldwide in their intestines. However the virus has mutated into the most fatal strain of influenza virus, known as H5N1, which is the strain causing so much havoc in the world and especially China today. Outbreaks of the highly pathogenic strain began in Southeast Asia in mid-2003 and are the most severe on record. Infected birds pass on the virus through their saliva, nasal secretions and faeces. Consequently other birds pick up the disease through direct contact with the infected bird excretions or contaminated surfaces, and spread it throughout the world during flights of migration. In a short period of time this will ultimately cause a pandemic. Pandemics are such dreaded events as they can rapidly infect all countries and once the virus spreads internationally it is considered unstoppable. Countries in Asia and especially China are most at risk to the latest outbreak of H5N1 due to flight migration patterns of infected birds as seen in this map. Crowded factory farms and unhygienic conditions of backyard farming and urban informal marketing also contribute to the spread of H5N1. In a short period of time, the Bird Flu will have devastating effects on the world environmentally, economically and socially. H5N1 is having devastating effects on China environmentally, although the total impact has yet to be determined. All birds are highly susceptible to the Bird Flu, hence the name, and will cause severe even fatal symptoms. The main symptoms in birds or poultry include depression, loss of appetite, cessation of egg laying, nervous signs, blue discolouration of the comb, coughing, sneezing and diarrhoea, however sudden death can occur without any previous signs of symptoms. A local from China recounts the symptoms of an infected bird, “They were starting to shake and their face turned purple, almost black. The eyes were swollen and turned red, then there were tears dropping out from their eyes. There were saliva came out from the mouth. Very sticky too. And then they started to die.” In addition to death, loss of income to small-scale farmers, caused by the virus infecting their chickens, may trigger efforts to farm more intensively and on more marginal 2006-07-30T03:16:34-04:00 http://75.150.148.189/free-essay/avian-influenza--30802.aspx Analysis of the Extracellular and Enigmatic Myxazoa The phylum Myxozoa falls under the domain Eukarya and were traditionally thought of as protozoa. Within the last two decades however more advanced identifying techniques have led us to believe that they are in fact metazoans more closely related to Cnidarians, but this will be discussed later in this essay. There are approximately twelve thousand species of Myxozoa, and it is believed that there may be more than this number. Most Myxozoa are parasites which inhabit primarily tissues and organ cavities of ectothermic vertebrates, especially fish, and can cause major problems within fish farms and hatcheries. Myxozoans are extra cellular parasites of ectothermic vertebrates and invertebrates. They mainly infect fish especially salmonoids, but do also infect some amphibians, reptiles and annelids. In fish they are found in cavities such as gall bladder, urinary tract, ureters or tissues including – cartilage, muscle gills and skin. In Annelids they can be found in the intestinal epithelium. Myxozoans have multicellular spores which contain two or more shell valves which join at a sutural plane, a sporoplasm that is infective to the host, and polar capsules containing polar filaments coiled within. Once ingested these polar filaments are then be expelled and it is thought that they are used as a means of attachment to the host. The most well known species of Myxozoa is the Myxobolus cerebalis due to its affect on salmonoids farms and hatcheries as it is responsible foe significant losses of stock. It affects the cartilage and nervous systems of many salmonoids worldwide. Nearly all Myxozoa have a typical lifecycle common amongst most organisms of the phylum normally involving two host species. The life cycle of Myxobolus cerebalis ids the best example as it is the most known about and most others follow essentially the same pattern. Spores released by the host species (salmonoids usually) are ingested by a tubificid oligochaete. The polar filaments within the polar capsules of the spore are then everted and the spores release the infective sporoplasma. During development within the oligochaete a form of sexual reproduction occurs along with the production of triactinomyxon spores. These new spores are released into the environment along with the host faeces. These spores were until recently believed to be a different species. When the next host, a salmonoids 2006-07-28T18:32:02-04:00 http://75.150.148.189/free-essay/Analysis-of-the-Extracellular-and-Enigmatic-Myxazoa-30771.aspx Biology Lab Report: Genetic Exchange in Prokaryotes This lab deals with the process of genetic exchange in prokaryotes. There are three main mechanisms of genetic exchange which include transformation, transduction, and conjugation. In transformation, DNA is released from cells in the surrounding environment which is then incorporated into the recipient cells DNA. In transduction, DNA is transferred through a virus to the recipient. In conjugation, genetic exchange occurs through direct contact with another cell and the plasmid is transferred from the donor to recipient. Plasmids are circular modules of double-stranded DNA which are beneficial but not essential. R factors are plasmids which carry genes that confer resistance to antibiotics on the host cell. R factors have been a problem because they are causing many strains of pathogenic bacteria to be highly resistant to antibiotics. Transformation was the first mechanism of bacterial exchange that was discovered. A famous experiment with transformation dealt with injecting mice with an avirulent strain of bacteria with heat-killed cells of a virulent strain killed the mice while injecting these strains separately did not. This established that the surviving cells were recombinant. A genetic exchange of the DNA in the external medium had occurred between the dead cells and the live ones. The bacteria that we are using is E. coli bacteria which are capable of being artificially transformed. They are made competent (capable of being transformed) only after following subjection of cells to calcium chloride solution. II.Transformation of E. coli A. Summary – In this lab, we are investigating the method of genetic exchange called transformation through the insertion of plasmid pUCB DNA, which carries the gene for antibiotic resistance to ampicillin, into competent E. coli cells. B. Procedure – The procedure of this lab is somewhat complicated. 250uL of calcium chloride to 2 separate tubes labeled + and --. Next, transfer a large colony of bacteria from the starter plate to the tube of cold calcium chloride and twirl rapidly. Add 10uL of the plasmid solution to the "+" tube. Then, incubate both tubes on ice for 15 minutes. During this time, obtain 2 Luria agar plates and two Luria agar plates with ampicillin. Label one plate "+" and the other "--". Next, remove the tubes from ice and immediately 2006-07-25T15:37:57-04:00 http://75.150.148.189/free-essay/Biology-Lab-Report-Genetic-Exchange-in-Prokaryotes-30640.aspx Lab Report on Cell Biology I made my cell project by myself. It took me 1 day to build it. I made the Mitochondria out of a dark blue glass squiggle, I made the Vacuole out of a light blue glass squiggle, I made the Golgi Complex out of a dark red string of yarn, and the Lysosomes were made out of a light blue pebble. I 2006-07-25T12:57:50-04:00 http://75.150.148.189/free-essay/Lab-Report-on-Cell-Biology--30634.aspx Analysis of Genetically Altered Food “Biotechnology involves any technique that uses living organisms or parts there of to make or modify products, to improve plants or animals or to develop micro organisms for specific uses” In the past century humans have been lucky enough to stumble upon one of the basic building blocks of organisms, DNA. In recent years scientists have been able to develop ways in which they can manipulate, alter, and transfer DNA in forms that can help improve our lives. One way in which DNA research has been used to improve our lifestyle, is by engineering the deoxyribonucleic acid into ways which can alter food supplies to make them bigger, taste better, resistant to pests and even make them have a greater concentration of nutrients. Of course this is great news to the human population, but there are still a few disadvantages. With all the good news these altered crops provide for humans, concerns are still among people. These concerns include; whether or not these alterations will affect humans in a negative way, and what impact they will have on the environment. Although no one can know for sure., the effects of these genetically engineered crops are probably overstated. Bioengineered crops could play a significant role in increasing crop production which will allow the world to feed more people and do it using less land. A recent study on bioengineered crops concluded that these crops are safe and can improve production dramatically. Those opposing the genetically altered crops state that “when altered DNA molecules are introduced into a living organism in the filed, the full range of their effects cannot be predicted or known before commercialization (over)." In the near future, shoppers will be able to find foods that last longer, taste better and are more nutritious than the foods currently eaten. And an even greater variety of foods all year round. These products will be made possible through biotechnology, and some of them are already available. For centuries, farmers grew plants to produce special foods with unique characteristics: better taste, higher yield or greater resistance to drought or frosts. “History shows that five thousand years ago in Peru, potatoes were grown selectively. Plants, which produced potatoes with desirable characteristics, such as higher yields, were used to produce future plants. 2006-07-23T19:53:25-04:00 http://75.150.148.189/free-essay/Analysis-of-Genetically-Altered-Food-30558.aspx Research on Brazilian Toucans Toucan is the Brazilian name for a bird of the family, Ramphastidae, with approximately 42 different species of the bird. These peculiar birds belong to the order Piciformes, whose members have feet with the first and fourth toes reversed and are all cavity nesters. The toucan is an unusual –looking bird, characterized by an enormous but light-weight bill, that has many useful qualities. Most species, posess a brilliant solid or multi-colored bill. They live in the tropical and subtropical forests of Central and South America, especially in the Amazon regions. Toucans are intelligent, curious and entertaining creatures. Eventhough they do not have the ability to mimic speech, they are playful and can be taught to perform tricks, including catch. The most common toucans in the wild include, the Keel Bill, Toco, and the Yellow Throated Toucan. Commonly available pet species include, the Toco, Red Bill, Keel Bill and Channel Bill Toucans. . The Toucan is an attractive neotropical bird, whose large slender body can be approximately 33 to 64 centimeters long. They have rounded wings with a small tail. Their bill may be as long as their body and appear in any colorful variation. The bill of a Toucan may be black, blue, brown, green, red, white, yellow, or any combination of colors. Toucans use their colorful bill to attract their mate. Their broken pattern also allows the bird to camoflage itself among the panorama of the forest colors. The canoe- shaped bill of a Toucan appears to be heavy, but is actually light, containing many air pockets. The edges of the bill are serrated, to allow the bird to skin fruit, drill wood, probe in the mud or tear flesh, as necessary. Inside the bill, is a long, narrow, feather-like tongue. The toucan can be easily found by listening for their loud croak, which can be heard up to half a mile away. Most species of toucans live in small flocks of generally 6 to 8 and sleep in hollow trees. When a toucan sleeps, they turn their head around and place their bill down the center of their back, then fold their tail over their head. Most species of toucans mate once a year, nesting in a hollow tree. Although the nest 2006-07-23T16:28:54-04:00 http://75.150.148.189/free-essay/Research-on-Brazilian-Toucans-30518.aspx Study on the Human Sense of Smell "What I remember most vividly is the aroma of toast at the old drugstore lunch counter. It was like no other. I don’t know why; we toasted the same white bread at home, but it never smelled as good or as intensely as it did in the drugstores. Maybe it was the high-volume buildup that did it. I loved that aroma. It made me feel good just to inhale it. Sometimes today, I’ll walk blocks out of my way to shop for something I don’t need at Kaufman’s on Lexington Avenue – the only pharmacy I know of that still maintains a real lunch counter – to drink in that toasty aroma" (qtd. in Engen 1991). Sniff a rose or freshly cut grass. Scents evoke many images and sensations so common we don’t even give them much thought. The olfactory system, which senses and processes odors, is one of the oldest and most vital parts of the brain. Despite the tendency of humans to underestimate the role of smell in our every day lives, for most mammals, smell is the most important sense. Dogs are probably the most obvious example of this, it is their primary mode of communication and influences many important functions, including reproduction and taste. Scientists are just beginning to learn how the olfactory system works. At the time Rachel Herz began her work with Olfaction, there had been relatively few studies on odor and memory (Holloway 1999). Researchers knew that the olfactory system was unique among the senses and that the primary olfactory cortex, in which higher-level processing of olfactory information takes place, forms a direct link with the limbic system, including the amygdala and hippocampus (Weiten 2000). Researchers could also trace the physiological path of a smell through the brain. It was known that after an odor molecule enters the nose and is recognized by the olfactory sensors, the signals are eventually sent to the olfactory bulb that is located right above the eyes (Passer 2001). The signals only go to two areas in the olfactory bulb, and signals from different sensors are targeted to different spots that then form a sensory map. From there the signals reach the olfactory area of the cortex (2001). An important quality of the olfactory system 2006-07-23T16:25:11-04:00 http://75.150.148.189/free-essay/Study-on-the-Human-Sense-of-Smell-30516.aspx Pros and Cons to Biological Pesticides What are Biopesticides? Biopesticides (also known as biological pesticides) are certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals. For example, garlic, mint, and baking soda all have pesticidal applications and are considered biopesticides. At the end of 1998, there were approximately 175 registered biopesticide active ingredients and 700 products. Biopesticides fall into three major categories: 1) Microbial pesticides contain a microorganism (bacterium, fungus, virus, protozoan or alga) as the active ingredient. The most widely known microbial pesticides are varieties of the bacterium Bacillus thuringiensis, or Bt, which can control certain insects in cabbage, potatoes, and other crops. Bt produces a protein that is harmful to specific insect pests. Certain other microbial pesticides act by out-competing pest organisms. Microbial pesticides need to be continuously monitored to ensure they do not become capable of harming non-target organisms, including humans. Microbial and Antimicrobial Pesticides: These are two separate and distinct types of pesticides registered by EPA. Microbial Pesticides are microbes, including bacteria, that help to control insects and weeds, as well as fungi and bacteria that cause plant diseases. These are one type of biopesticide. Antimicrobial Pesticides are pesticides that control unwanted microbes on inanimate objects, in water, and on selected foods under certain circumstances. These pesticides are almost always chemicals, and they act by killing or inactivating microbes that are pests. Antimicrobial pesticides include the disinfectants used in swimming pools, drinking water supplies, and in hospitals to control microbes that can cause disease. 2) Plant-pesticides are pesticidal substances that plants produce from genetic material that has been added to the plant. For example, scientists can take the gene for the Bt pesticidal protein, and introduce the gene into the plants= own genetic material. Then the plant B instead of the Bt bacterium--manufactures the substance that destroys the pest. Both the protein and its genetic material are regulated by EPA; the plant itself is not regulated. 3) Biochemical pesticides are naturally occurring substances that control pests by non-toxic mechanisms. Conventional pesticides, by contrast, are synthetic materials that usually kill or inactivate the pest. Biochemical pesticides include substances that interfere with growth or mating, such as plant growth regulators, or substances that repel or attract pests, such as pheromones. Because it is sometimes difficult to determine whether a natural pesticide controls the pest by 2006-07-23T13:51:03-04:00 http://75.150.148.189/free-essay/Pros-and-Cons-to-Biological-Pesticides-30514.aspx The Biology of Survival According to Charles Darwin, the various species and individuals compete for the same territories, and thus organisms that are better adapted to their environment are more likely to survive, reproduce, and transmit their features or traits to the next generation. Ø Ability to reproduce efficiently In actuality, there are a few brain structures that give humans the arousal, desire, and necessity to reproduce. However, the Reticular Activating System and the Hypothalamus are particularly responsible for these needs. The Reticular Activating System serves primarily for arousal, while the Hypothalamus produces sexual behavior and mating desire. This is perhaps the most important factor of human survival, without these instincts and desires there would be no future for the continuation of human life. Ø Ability to communicate superior to any other animal Humans are able to communicate on the highest intelligible level ever known, we are able to communicate with body language, sign language, code and symbol language, and spoken language. The main part of the brain that instills us with this ability is the cerebral cortex. Humans are able to decipher speech (left cortex) and the imagery (right cortex) with cerebrum. Communication is essential to increasing knowledge from generation to generation, thus making humans the most intelligible of all animals. The main difference between human knowledge is that it can be taught, whereas all other animals have to re-learn what their parents learned. Humans are able to take over where the last generation left off because of our ability to communicate. Ø Ability to adapt to almost any environment on earth The hypothalamus limits and controls motivation and body temperature; the cerebrum also gives humans the ability to think, reason, and survive. Both of these structures are necessary for adaptation or migration to survive. Most animals are only capable of surviving in their natural habitat- or another habitat closely related, but humans have the ability to survive just about anywhere. This is so, because humans are equipped with enough reasoning that we can decide to protect ourselves from the environment. We are able to make clothing, artificial heat, and houses to keep us warm, we are able to realize if our body temperature is getting too high or low, we are able to make oxygen if there is not 2006-07-22T13:38:46-04:00 http://75.150.148.189/free-essay/The-Biology-of-Survival--30465.aspx The Ecosystems that Thrive in Hydrothermal Vents Some 7,500 feet below the ocean’s surface lies a intriguing and bizarre world unlike any other. Large black volcanoes tower above the ocean floor spouting out poisonous black gas into freezing cold waters and blind crabs roam endlessly in pitch darkness. These intolerable conditions could only mean one thing, hydrothermal vents. These mystical giants of the deep have stumped some of the worlds greatest scientists who have only recently discovered that they may hold the potential key to some of the worlds great scientific mysteries such as how an ecosystem can survive with out sunlight and the possible origin of life. Only by studying and understanding hydrothermal vents will we be able to start to unlock some of these puzzles. In discovering hydrothermal vents, many more questions arose. One of which relates to the excruciating circumstances organisms that inhabit these vent sites survive under. This includes how they are able to withstand poisonous toxins, unbearable temperatures, outstanding pressure, possess the ability to gather food and reproduce effectively. One of the finest examples of these amazing organisms is the tube worm. But before we tackle the many questions surrounding this unusual creature it is best to understand the environment it thrives in. History of Hydrothermal Vents Recently scientists began an in depth study on the potential existence of hot water vents. While the existence of the mid ocean ridges were known, some believed a similar type of vent resided that was supported by a hydrothermal system. From as early as 1972 scientists began taking water samples that indicated the presence of these hot water vents (Chu). Using this technique scientists gained strong evidence that one of these vents was sitting along the Galapagos Rift. On an expedition in 1977 a group of scientist fell upon a colossal discovery that gave proof to the outlandish theory (Chu). Using a submersible named Alvin researchers were able to view the sea floor from the ocean’s surface through photographs. They were in for a tremendous suprize. Not only did Alvin reveal the presence of hydrothermal vents but of a whole ecosystem of life. This essential discovery shocked and dumbfounded scientists all over the world. For the next two years Alvin would journey back to vent sites to get a better understanding of their existence. In 1979 this amazing sub captured another intriguing image. A 65 foot, chimney 2006-07-22T10:51:17-04:00 http://75.150.148.189/free-essay/The-Ecosystems-that-Thrive-in-Hydrothermal-Vents-30420.aspx Endangerd Species of Bird: The Roseate Tern Like many other species the Roseate Tern is also endangered. These creatures are some of the world’s most beautiful animals and are slowly being killed by man and nature. The Roseate Tern somewhat resembles a sea gull with a slender body and short reddish legs. They have pointed wings and long streamer tails, like the streamer on a kite. Their bodies are a pale gray and are white with a pink tinge on their underside in the early breeding season. This tinge however, is not a good way to tell if a bird is the Roseate Tern since the sun can bleach the colors out. They also have a black forehead and nape. Their upper wings are gray and have distinctly forked wings like that of a swallow. Their wingspan is about 72-80 centimeters and they weigh about 100-120 grams, which is slightly smaller that a mourning dove would be. Both male and female birds are similar in appearance; the only way to tell is that the male that isn’t breeding has a mixed black and white head. These bird life in quiet areas and live in small colonies. Areas where they can hide easily are taken advantage of. Places with things like dense grasses or other vegetation are the most common nesting sites. If these birds are disturbed in their nesting area, they will most likely abandon the site where their eggs are laid and predators will eat them. The most common areas where these nesting sites are found are in tropical areas such as the Indian, Pacific, Atlantic Oceans, South Africa and Western Australia. They can also like in the hotter areas of North America and Europe. The birds’ population was first dramatically changed in the 1980s when they were hunted for feathers. Due to hunting the population become about 2000 pairs in total. In the 1930s that grew to 10500 due to protective legislation to prevent further damage to the threatened species. Around 1950 again the population went down to only 3800, this time it was due to loss of habitat where the birds had a hard time finding quite nested areas. There are about 50 00 pairs in the world at this time but the population is still gradually decreasing, from both Human disturbance 2006-07-17T13:00:08-04:00 http://75.150.148.189/free-essay/Endangerd-Species-of-Bird-The-Roseate-Tern-30288.aspx Mitochondria's Evolution from the Chloroplast I discovered that mitochondria evolved from the chloroplast (Audersirk p. 369). “The endosymbotic hypothesis championed most forcefull by Lynn Margulis of the University of Massachusetts, propose that cells acquired the precursors of mitochondria and chloroplast by engulfing certain types of bacteria.” This happens by the aerobe bacteria that absorbs those molecules and used energy oxygen to complete their metabolism. By gaining a high range of energy, using large food resources, great amount of energy leak out a ATP and right back into the host of cytoplasm that is how mitochondria came about. The role of the mitochondria in our are bodies is to process oxygen, convert fatty acids. Carbohydrates, and proteins from food that we eat turns into energy. The body’s mobile energy source is ATP (adenosine triphosphate). Within the mitochondria it has its own DNA. What mitochondria with DNA all thisis new to me. An a article in the newspaper the mentioning the role of mitochondria DNA causing genetic diseases. I could not believe my eyes, after reading the article I had in mind that the Mitochondria DNA was the same as the Nuclear DNA, not true at all. Mitochondria DNA verses Nuclear DNA. Nuclear DNA has twenty TRNA ( transferal RNA) proteins that are free radicals, which encodes of the subumits of oxidative phosphorylation. Whereas, Mitochondria DNA has twenty-two tRNA with no proteins. Nucleat DNA has a linear shape DNA but Mitochondria DNA have a circular DNA. Since Nuclear DNA has both extrons and introns the limitation of mutations are low. However, Mitochondria DNA only have introns, so Mitochondria DNA mutate to occur in the cell. Mutations occur in mitonchondria. When the vital supply of ATP is disrupted less and less energy is generated within the cell, the process is repeated continuous the body system begins to shut down. In further detail, in the mitochondria there are two through ten molecules that exist and each cell contains multiple mitochondria within that cell. There can be normal and mutant Mitochondria DNA. (New England Journal…) There is a condition known as hetroplasmy that allow otherwise lethal mutations to persist. Homplasmy is the presence of either completely normal or completely mutant Mitochondria DNA. An individual may be life-treaten. “Mutations with the 2006-07-16T22:05:16-04:00 http://75.150.148.189/free-essay/Mitochondria-s-Evolution-from-the-Chloroplast-30270.aspx Overview of Stem-Cell Research After a brief study of stem cell research, I discovered that it is a largely debated topic and that many find it ethically wrong. I certainly understand the perspective of those morally opposed to the research, however I concluded that the positive aspects of the research far outweigh the negatives. Most of those who are morally opposed to the research believe that the embryo has the moral status of a person from the moment of conception. Similar to opponents of abortion in relation to the fetus, they think that research (or any other activity) that would destroy the embryo is wrong. Many of those who condemn the research fail to realize that the embryos are typically extracted from surplus frozen embryos left over from in-vitro fertilization procedures at fertility clinics. For those who support the research, 2006-07-13T19:17:10-04:00 http://75.150.148.189/free-essay/Overview-of-Stem-Cell-Research-30241.aspx Questions Concerning Human Development Throughout life a person goes through a process called growth. Everyone grows at a different rate. However everyone goes through the some of the stages of life. Cells make up all living lives. Cells are the basic units, or building blocks of life. Everyone and everything is made up of billions of cells. Every cell in your body does a specific job. Cells that do similar jobs form tissues. The body is made up of many kinds of tissues. Nerve tissues and muscle tissues are just a couple examples. Like cells tissues are combined into larger structures called organs. Organs are body parts like the stomach brain or lungs. Groups of organs that work together are called systems. The body has several systems too like digestive or respiratory for example. Sometimes you wonder why am I am like I am? There are a number of factors that answer this question. Two of the most important factors are heredity and environment. Heredity is the passing of traits from your parents. Environment is the area around you. There is also chromosomes. Chromosomes are the tiny structures found within cells that determine the specific type of person you turn out to be. Insides chromosomes are genes. Genes are tiny bits of matter that control which traits of your parents gets passed down to you. Sometimes when a woman is pregnant she doesn’t do everything she is supposed to do and when the baby is born it might have a disease like fetal alcohol syndrome. For a baby to hopefully turn out right the mother should eat right, get enough rest, get enough exercise, and avoid all drugs and tobacco. Sometimes though it isn’t anybodies fault the baby can be born with genetic disorder. That is a disease or condition in which the body does not work normally because of a problem with genes. Several hundred thousand babies are born each year with a genetic disorder and it isn’t anybodies fault. The first year of life is when the fastest physical growth takes place. The weight of the child triples and the height doubles. During infancy trust develops. Infancy is the first years of life. The child needs loving care and they need to trust you and know that they are safe. 2006-07-09T14:14:56-04:00 http://75.150.148.189/free-essay/Questions-Concerning-Human-Development-30123.aspx Biological Study of Gotu Kola Plant Gotu Kola is a slender, creeping plant that grows commonly in swampy areas of India, Sri Lanka, Madagascar, South Africa and the tropics. Its fan shaped leaves are about the size of an old British penny - hence its common names Indian pennywort, marsh penny and water pennywort. It is regarded as one of the most spiritual and rejuvenating herbs in Ayurveda and is used to improve meditation. It is said to develop the crown chakra, the energy center at the top of the head, and to balance the right and left hemispheres of the brain, which the leaf is said to resemble. Gotu kola has been widely used for a number of conditions, particularly in traditional Eastern health care. In Ayurveda Gotu kola is one of the chief herbs for revitalizing the nerves and brain cells. It is said to fortify the immune system, both cleansing and feeding it, and to strengthen the adrenals. It has been used as a tonic for purification of blood and for promoting healthy skin. It has also been used to aid in restful sleep, treat skin inflammations, as a treatment for high blood pressure and as a mild diuretic. Recent studies (1995) demonstrated that Gotu kola destroyed cultured tumor cells in the laboratory setting (in vitro). The leaves of this swamp plant have been used around the world for centuries to treat leprosy, cancer, skin disorders, arthritis, hemorrhoids, and tuberculosis. In recent years, Gotu kola has become popular in the West as a nerve tonic to promote relaxation and to enhance memory. The herbs calming properties make it well suited for overcoming insomnia and making one calm for yoga and meditative practices. It is commonly used to rebuild energy reserves improve memory and treat fatigue, both mental and physical. Gotu kola has been referred to as "food for the brain". This oriental herb has demonstrated mild tranquilizing, anti-anxiety and anti-stress effects, as well as improving mental functions such as concentration and memory. It has a calming effect on the body and is chiefly used to support the central nervous system. These beneficial qualities make Gotu kola an excellent herb for children with A.D.D. because it has a stimulating effect on the brain that increases one's ability to focus while having a soothing and relaxing effect on an overactive nervous system. Gotu 2006-07-09T13:46:03-04:00 http://75.150.148.189/free-essay/Biological-Study-of-Gotu-Kola-Plant-30113.aspx Important Information about Anthrax Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Anthrax most commonly occurs in warm-blooded animals, but can also infect man. Anthrax spores can be produced in a dry form (for biological warfare ) which may be stored and ground into particles. When inhaled by humans, these particles cause respiratory failure and death within a week. Why has anthrax become a current issue? Because anthrax is considered to be a potential agent for use in biological warfare, the Department of Defense (DOD) announced that it will begin systematic vaccination of all U.S. military personnel. Who gets anthrax? Anthrax is most common in agricultural regions where it occurs in animals. These include South and Central America, Southern and Eastern Europe, Asia, Africa, the Caribbean, and the Middle East. When anthrax affects humans, it is usually due to an occupational exposure to infected animals or their products. Workers who are exposed to dead animals and animal products (industrial anthrax) from other countries where anthrax is more common may become infected with B. anthracis. Anthrax in animals rarely occurs in the United States. Most reports of animal infection are received from Texas, Louisiana, Mississippi, Oklahoma and South Dakota. How is anthrax transmitted? Anthrax infection can occur in three forms: cutaneous (skin), inhalation, and gastrointestinal. B. anthracis spores can live in the soil for many years and humans can become infected with anthrax by handling animal products from infected animals or by inhaling anthrax spores from contaminated animal products. Anthrax can also be spread by eating undercooked meat from infected animals. It is rare to find infected animals in the United States. What are the symptoms of anthrax? Symptoms of disease vary depending on how the disease was contracted, but symptoms usually occur within seven days. Cutaneous: Most anthrax infections occur when the bacterium enters a cut or abrasion on the skin, such as when handling contaminated wool, hides, leather or hair products (especially goat hair) of infected animals. Skin infection begins as a raised itchy bump that resembles an insect bite but within 1-2 days develops into a vesicle and then a painless ulcer, usually 1-3 cm in diameter, with a characteristic black necrotic (dying) area in the center. Lymph glands in the adjacent area may swell. About 20% of untreated cases of cutaneous anthrax will result in death. Deaths are rare with appropriate antimicrobial 2006-07-05T23:34:55-04:00 http://75.150.148.189/free-essay/Important-Information-about-Anthrax-30050.aspx Assessing Man's Evolution The origins of man is an extremely controversial issue within today’s society. Scientists have a host of different theories pertaining to man’s inhabitance of earth. Many disagreements arise between scientists who have different beliefs pertaining to where and how mankind arose. One such argument is the conflict involving the theory of evolution versus the theory of creation. After extensive scientific research, it is apparent that the theory of evolution is correct. Evolution is the theory that life arose by natural processes at an early stage of the earth’s history and that complex organisms developed from simpler organisms by a process of slow change (Coren 209). It’s the idea that new species arise from older species after thousands of years of gradual chemical, environmental, and genetic change (Coren 142). Evolution can also be described as the complex processes by which living organisms originated on earth and have been diversified and modified through sustained changes in form and function (“Evolution”). Scientists, looking for an explanation to the origin of man and other organisms created this evolutionism theory, which also presented answers to the many asked questions dealing with similarities between species. Unlike the theory of creation, which states that the complexity of life and different species can only be explained in terms of a supernatural creator or god who placed life on earth, the theory of evolution has a plethora of evidence proving it to be true (“Creation”). There are several different types of observations that support the theory of organic evolution as an explanation for the similarities and the differences among species. One such observation is in the geologic record. The geologic record is the rock scheme found within the earth’s outer crust. By means of radioactive dating, the ages of rocks in many places on earth have been determined. It’s a timetable of the earth’s geologic history. This combined with the fossil record, another observation supporting the evolutionary hypothesis, has produced an apparent sequence of life forms from most simple to most complex during the history of the planet. Fossils are any remains or traces of a once-living organism, which are formed by preservation, petrifaction, or sedimentation. Organisms can be preserved and protected against decay by being trapped in amber, tar, or frozen in ice. The hard parts of an organism, such as shells or bones, can be preserved when the flesh of an organism has decayed away. In 2006-07-04T16:38:07-04:00 http://75.150.148.189/free-essay/Assessing-Man-s-Evolution-30005.aspx Biological Inspection of Cell Membranes The plasma membrane is the boundary of life; this selectively permeable membrane allows the cell to maintain a unique internal environment and to control the movement of materials into and out of the cell. The phospholipid bilayer (fluid mosiac model) with specific membrane proteins accounts for he selective permeability of the membrane and passive and active transport mechanisms. Membrane phospholipids are amphipathic. Cell membranes are phospholipid bilayers with the hydrophobic hydrocarbon tails in the center and the hydrophilic heads facing the aqueous solution on both sides of the membrane. The phospholipid bilayer also called the fluid mosiac model has proteins embedded in the phospholipid bilayer with their hydrophilic regions extending out into the aqueous environment. Membranes are held together by weak hydrophobic interactions that allow the lipids and some of the proteins to drift laterally. Phospholipids with unsaturated hydrocarbon tails maintain membrane fluidity at lower temperatures. The steroid cholesterol restricts movement of phospholipids, therefore, reducing fluidity at warmer temperatures. Cholesterol also prevents the close packing of lipids and thus enhances fluidity at lower temperatures. The plasma membrane permits regular exchange of nutrients, waste products, oxygen, and inorganic ions. Membranes are selectively permeable which means that they allow some substances to cross more easily than others. Hydrophobic molecules, such as hydrocarbons, can dissolve in and cross through a membrane. Very small polar molecules, including water, can cross a plasma membrane easily. Ions and polar molecules may move across the plasma membrane with the aid of transport proteins, which may provide a hydrophilic channel or may physically bind and transport a specific molecule. The selectively permeability of a membrane depends on both the discriminating barrier of the lipid bilayer and the specific transport proteins built into the membrane. The structure of membranes is directly related to the transport of materials across a membrane. Diffusion is the spontaneous movement of a substance down its concentration gradient. The cell does not expend energy when substances diffuse across membranes therefore, the process is called passive transport. Osmosis is the diffusion of water across a selectively permeable membrane. Water diffuses down its own concentration gradient and water will move from a hypotonic solution across a membrane into a hypertonic solution. Specific proteins facilitate the passive transport of selected solutes. Facilitated diffusion involves the diffusion of polar molecules and ions across a membrane with the aid of 2006-07-03T23:37:41-04:00 http://75.150.148.189/free-essay/Biological-Inspection-of-Cell-Membranes-29965.aspx Symptoms of Chronic Leukemia Chronic myelogenous leukemia (CML) is one of the four most common types of leukemia and is responsible for 15 to 20 percent of all adult leukemia’s. CML is a deadly cancer of the bone marrow cells that causes white blood cells to increase to more than twelve times their limit, at an uncontrollable rate. Normally, this can lead to fatigue, fever, and a fatal 5-year survival rate. Novartis Oncology Pharmaceuticals, the second largest drug company in the world, with headquarters in Switzerland, is the main company investigating a new drug to cure CML, called STI-571 (Gleevec). This drug has taken on many names such as Glivec, Imatinib Mesylate, CGP57148B, but due to nomenclature issues with the F.D.A., the drug is now named Gleevec. Novartis’ primary goal of their studies was to discover an ability to treat cancer by eliminating only the cancer cells with minimal or no effects on normal cells. From many years of research, doctors have successfully created the drug Gleevec, which does just that. Gleevec selectively blocks mutant enzymes that cause CML without harming its molecular correspondents. Gleevec has been put into the class of “cytostatics.” Cytostatics are designed to focus in on cancer cells without harming healthy ones. This is significantly more effective when compared to the normal treatments of leukemia such as radiation and bone marrow transplant. Specifically, Gleevec disrupts the Abelson kinase (Abl) from its accidental activation. This then leads to CML by activating other proteins by adding phosphate to them in a process called phosphorylation. Kinase plays an important role in regulating cell growth and division. Gleevec inactivates the Abelson kinase by binding to it, thus inhibiting it to reproduce. Gleevec works by blocking signals within cancer cells that contain Abl and prevents a series of chemical reactions that cause or signal the cell to grow and divide. With these results, doctors agree that with these same ideas, the pill can be adapted to cure various types of other cancers. Gleevec has already been used in clinical trials to cure certain types of brain and stomach cancers. Gleevec is still at a relatively early phase of clinical testing and has recently been submitted to the F.D.A. for further tests to determine its effectiveness on February 27, 2001. According to the F.D.A., approval for Gleevec can take up to six months before it is available on the market for patients. If 2006-07-03T22:59:07-04:00 http://75.150.148.189/free-essay/Symptoms-of-Chronic-Leukemia-29946.aspx The Process of Human Digestion Digestive System, series of organs put together that purpose is to break down, or digest, the food we eat. Food is made up of large things called, complex molecules, which the digestive system breaks down into smaller things called simple molecules that get absorbed into the bloodstream. The bloodstream is our blood. The simple molecules travel through the bloodstream to all of the parts of the body, which we use for growth, repair, and energy. All living things that eat to get energy have a digestive system, a feature that makes us different from plants. Plants make their own food in a process called photosynthesis, photosynthesis is when plants make sunlight to convert water and carbon dioxide into simple sugars. But animals, including humans, must take in food in the form of organic matter, such as plants or other animals. Digestion generally involves two parts: a mechanical part and a chemical part. In the mechanical part, teeth physically break down large pieces of food into smaller pieces. In the chemical part, digestive chemicals called enzymes break apart individual molecules of food to yield molecules that can be absorbed and distributed throughout the body. These enzymes are secreted by glands in the body. The digestive system of most animals consists mainly of a long, tube called the alimentary canal, or digestive tract. This canal has a mouth at one end, through which food is taken in, and an anus at the other end, through which pup is taken out the body.. Muscles in the walls of the alimentary canal move the food along. Most digestive organs are part of the alimentary canal. However, two digestive organs, the liver and pancreas, are located outside the digestive system. These organs put in chemical digestion by releasing digestive juices into the digestion system through tubes called ducts. If an adult’s digestive tract were stretched out, it would be 20 to 30 ft long. In humans, digestion begins in the mouth, where both mechanical and chemical digestion occur. The mouth quickly turns food into a soft, moist mass. The muscular tongue pushes the food against the teeth, which cut, chop, and grind the food. Glands in the cheek linings secrete mucus, which lubricates the food, making it easier to chew and swallow. Three pairs of glands empty saliva into the mouth through ducts to moisten the food. 2006-07-03T13:45:09-04:00 http://75.150.148.189/free-essay/The-Process-of-Human-Digestion-29928.aspx Study of the Hippopotamus Amphibious Hippos have historically been found throughout all of Africa. Currently most populations have been greatly reduced. The only large population of hippos lives near the Nile river valley of east Africa. The scientific name for hippo is hippopotamus amphibious. Hippos are about four and a half feet tall and eleven feet long. They weigh about three to seven thousand pounds and are the second largest land mammal. A hippos skin is gray- brown. The upper parts are blue- black and the under parts are pink. Hippos have glands inside their skin that release thick red oil, the oil shields against sunburn. Hippos have excellent hearing, sight and smell. They also have fine hair that covers their entire body. The eyes and ears are small, set far back and high on the head. The neck is short with many folds of skin on it. A hippos muzzle can measure up to fifty centimeters wide. Each foot has four toes with thick nails on it. The tail is short and flat with thick bristles on the end. Males are much larger than females with thicker necks, more skin folds and larger tusks. Hippos need water to submerge in, but they can temporarily survive in mud holes. They spend their days in the water to keep cool and avoid insects. They leave the water to sunbathe and eat. Hippos can swim on the surface of water or walk along the bottom, staying under water for up to six minutes. When they come to the surface they exhale by grunting. Hippos can move very fast. They are active on land at night for five to six hours when grazing. They strictly eat grass. If there is a food shortage they will eat floating water plants. A hippo’s life span is thirty-five to forty-five years. They mate in the dry season. Females give birth in shallow water. The young are reported to be able to swim before they can walk. Baby hippos lie across their mother’s back in deep water. Hippos live in schools of thirty. There is a single nt bull that defends their stretch of water. Their tusks are used to fight, stabbing the thick 2006-07-02T22:29:59-04:00 http://75.150.148.189/free-essay/Study-of-the-Hippopotamus-Amphibious-29906.aspx Biology of the Galapagos Giant Tortoises The giant tortoise is probably the best known of all Galapagos animals and even gave the archipelago its name; 'Galapago' means tortoise in Spanish and may derive from the word for saddle, referring to the distinctive saddle-like shell of some of the tortoises. Galapagos giant tortoises can weigh up to 250 kg and live for more than 100 years. They are thought to belong to just one species, Geochelone elephant opus, with 14 different races or sub-species, three of which are believed to be extinct. Persecution In the 1600s, buccaneers started to use Galapagos as a base, restocking on water and repairing their boats before setting off to attack the Spanish colonies on the South American mainland. But the main attraction of the islands were the giant tortoises which were collected and stored live on board ship where they survived for many months, providing invaluable fresh meat. In the 1800s, whaling ships and then fur-sealers collected tortoises for food and many more were killed for their fine 'turtle oil' from the late 1800s until early this century. Early settlers then hunted them for their meat and cleared large areas of their habitat for agriculture. The settlers also introduced domestic animals, many of which went wild and had a disastrous effect on the tortoises. No-one knows exactly how many giant tortoises there were originally but it has been estimated that more than 100,000 were hunted in total over the centuries. The result today is that three races of Galapagos giant tortoise are extinct while just one individual survives from a fourth. There are about 15,000 tortoises left altogether. As the hunters found it easier to collect the tortoises living round the coastal zones, the healthiest populations today tend to be those in the highlands. Persecution still continues on a much smaller scale; more than 120 tortoises have been killed by poachers since 1990. Arrival It is likely that all the present races of giant tortoise evolved in Galapagos from a common ancestor that arrived from the mainland, floating on the ocean currents. Although this seems an incredible journey it is known that Galapagos tortoises can float easily in sea water. Only a single pregnant female or one male and one female needed to arrive in this way, and then survive, for Galapagos to be colonised. It is likely that the 2006-06-27T03:11:07-04:00 http://75.150.148.189/free-essay/Biology-of-the-Galapagos-Giant-Tortoises-29881.aspx Examining Endangered Frog and Toad Species The toad ranges in length from about 1 to 7 in. (2.5–18 cm). Although there is no clear-cut distinction between toads and frogs, the name toad commonly refers to those species that have relatively short legs, stout bodies, and thick skins, and are less aquatic as adults than the long-legged, slender-bodied frogs. They generally live in cool, moist places and absorb moisture through the skin. The white fluid that they send out through the skin is very poisonous and causes intense burning if it comes 2006-06-21T17:27:09-04:00 http://75.150.148.189/free-essay/Examining-Endangered-Frog-and-Toad-Species-29791.aspx Is Alcoholism a Hereditary Disease? Imagine yourself being 11 years old. You and your next-door neighbor just finished eating dinner, and now playing cards in front of the television. A few hours pass and your mother tells you that its bedtime. After being asleep for a couple of hours, you hear your father come inside your house. This was not unusual; he always comes home late at night. You hear your parents yell at each other and then you hear an awful sound. Did your father just hit your mother only because his dinner was cold, and he was late? You ask yourself why, why is he like this? He is like this because he is an alcoholic and cannot control his temper when he has been drinking. The next day you promise your mom and yourself that when you grow up you were never going to become an alcoholic. You see what your father’s alcoholism has done to your family and yourself and would never want that to happen to your family when you become an adult. Twenty years later, you too become an alcoholic. Children of alcoholics are four times more likely to grow up to be an alcoholic than any other children, according to the American Academy of Child and Adolescent Psychiatry. (NCADI: Fact is Alcoholism Runs in Families) One in five adult Americans lived with an alcoholic while growing up. (AACAP) Studies have shown that even twins separated at birth and living in two very different environments still became alcoholics. There were an estimated 28.6 million Children of Alcoholics (COAs) in the United States in 1991, nearly 11 million of them under the age of 18. Of the under 18-age group, there will be almost 3 million that will develop alcoholism and other drug problems. More than half of these teens will marry alcoholics and are likely to recreate the same kinds of highly stressful and unhealthy families in which they grew up. (NCADI) I am not saying that alcoholism is hereditary. It can and does skip some generations. What I am trying to say is that it definitely has genetic factors. Although, you become an alcoholic does not mean that your sister will become an alcoholic too. She might not have inherited that particular gene. If your mother was a good math student in high school, it does not mean that you will be good in math also. 2006-06-20T15:43:32-04:00 http://75.150.148.189/free-essay/Is-Alcoholism-a-Hereditary-Disease-29695.aspx Studying the Human Genome Project The Human Genome Project is a 15-year international research program to find the estimated 80,000 human genes and determine the sequence of the three billion DNA building blocks that underlie all of human biology and its diversity. The purpose of The Human Genome Project will characterize the genomes of human and selected model organisms through complete mapping and sequencing of their DNA. It will also develop technologies for genomic analysis and examine the ethical, legal, and social implications of human genetics research. Finally it will train scientists who will be able to utilize the tools and resources developed through the HGP to pursue biological studies that will improve human health. The Human Genome Project has several goals including mapping, sequencing, storing and analyzing data, identifying genes, and addressing the ethical, legal, and social issues that may turn out from availability of personal genetic information. The absolute goal of the Human Genome Project is to procure the DNA sequence of the three billion DNA subunits present in human DNA. The Human Genome Project started in October 1990 to discover all the estimated 100,000 human genes and make them accessible for further biological study. In 1992 a low-resolution genetic linkage map of entire human genome was published. In 1995, the genetic-mapping 5 year-goal achieved 1 year ahead of schedule. In 1997, high-resolution physical maps of chromosomes X and Y were completed. Then on December 1, 1999 researchers in the Human Genome Project announced the complete sequencing of the DNA making up human chromosome 22. Chromosome 22 is the first Human chromosome completed. These dates were just a few of the important events that has going on throughout the Human Genome Project. The process of the project has gone far in many years. Since technology is advancing the scientists will be able to speed up their work and complete the project sooner then scheduled. The progress toward the Human Genome Project sequencing goals is thirty-six percent of 3 billion DNA base pairs. Chromosome 1 is consisted of 839 genes. Chromosome 1 also consists of 34 pseudogenes. Some of the diseases associated with chromosome 1 are Alzheimer’s disease and Gaucher disease. Alzheimer’s disease is named after a German neurologist Alois Alzheimer. Alzheimer’s disease is the fourth leading cause of death in adults. Alzheimer’s disease is twice as common in women then in men. The circumstances of the disease worsen with age. 2006-06-15T16:01:40-04:00 http://75.150.148.189/free-essay/Studying-the-Human-Genome-Project-29541.aspx The Rain Forest Dweller the Kinkajou The kinkajou is a small honey-gold or brown animal that lives in the rain forest. In Mexico, it is called "Mico de Noche" because of the color of its fur. A few of the rain forests it lives in are in Brazil, Peru, Ecuador, Guatemala, Honduras, and much of Panama. The Kinkajou lives on the lower canopy an its stays in a tree almost all its life and very seldom, if ever, comes down. The kinkajou is sometimes called a Honey bear. Its fur is very soft and fluffy. It has a prehensile tail and is related to raccoons. They are very common in rain forest. It has a round head with small round ears and a cat-like face. The kinkajou also has a long stretchable tongue used for getting nectar. The tongue is about 5 inches long! The 2006-06-06T14:53:13-04:00 http://75.150.148.189/free-essay/The-Rain-Forest-Dweller-the-Kinkajou-29071.aspx Laboratory Write up on Photosythesis in Biology When you and me eat, we find our food. When plants eat, they make theirown food and energy. They make their food and energy through a process called photosynthesis. Through photosynthesis oxygen is also produced. Photosynthesis is "a process in which 2006-06-01T19:08:39-04:00 http://75.150.148.189/free-essay/Laboratory-Write-up-on-Photosythesis-in-Biology-28986.aspx Colon Cancer I. Introduction A. What is Colon Cancer? B. Another name for Colon Cancer? II. Body A. General Information 1. Risk Factor for Colon Cancer a. age b. Diet c. family medical history 2. Screening for Colon Cancer a. Method i. Sigmoidoscopy or Colonoscopy ii. Blood stool test 3. Symptoms of Colon Cancer a. Changes in Bowel movements b. vomiting c. Rectal Bleeding d. back pain 4. Prognosis a. The amount of damage to DNA in tumor cell may affect b. The pattern of movement of cancer cell into the intestinal wall may have an effect on outcome. 5. Treatment a. Exercise b. Intake of vegetables c. Medications d. Surgery e. CT scans III. Conclusion A. Risk Factor B. Screening C. Prevention References 1. Chanita Hughes Halber, PhD; Henry Lyuch, MD;…James &Archives. “Archives of Internal Medicine”. Vol.164 No 17.27 September 27, 2004. “Colon Cancer Screening practice following…” <http://archinte.ama_assn.org/cgi/content/abstract/164/17/1881? 2006-04-03T15:34:01-04:00 http://75.150.148.189/free-essay/Outline-on-Colon-Cancer-28654.aspx Cancer: Colon Cancer Human Physiology Colon cancer is considered as a pathophsiology disease. Cancer itself is an danger word to be heard by anyone and with colon attached to cancer, it could not sound any good. Any cancer is named according to the kind of organ tissue from which it develops million people, world wide, get different type of cancer every year. Colon cancer also known as colorectal cancer, is formed in the lining of the large intestine and rectum. The name “colorectal” is formed by colon and rectum. Colon plays an great rule in our digestive system. The colon is known to be responsible for absorbing water from what we eat, and in addition, for collecting food waste until we are able to digest it from the body. In the abdomen colon is shape of an upside-down “U”. In orders to treat a such an disease, one must learn the unique experience with symptom, diagnosis, different stages of colon cancer and the right treatment for an different stages that colon cancer is occurring. How one can define an such a disease as colon cancer? Nearly every disease has symptoms, and some symptoms may occur until the last stages of the disease. Symptoms of colon cancer include rectal bleeding, dark stools called melena, bowel movements, gas pains, back pain, and discharge from the rectum, As the tumor in the colon grows, it block which leads to later infections or bleeding in the abdominal cavity. As the tumor spreads, it can causes other types of problems, such as liver pains, loss of appetite, or other cancer of the organs. The diagnosed of colon cancer can be in many different ways. However, not many are getting tested for the disease until it is the screening for blood in stool is permitted, for people over the age of 50, even if they have no risk factors. Patient who are diagnosed with colon cancer can be tested by having a colonoscopy. Colonoscopy is a test in which doctors can look into the entire colon and collect tissue through the scope. Another test is endoscope where a small 2006-04-03T15:32:13-04:00 http://75.150.148.189/free-essay/Colon-Cancer-Research-Paper-28653.aspx Investigating Osmosis In Potato Cells Apparatus: The apparatus used in this experiment were: 1) 5 beakers, 2) 3 large potatoes (same type), 3) 15 pieces of potato without skin (roughly the same size), 4) 10 pins, 5) 50ml of distilled water, 6) 50ml salt solution 0.50, 7) 50ml salt solution 1.00, 8) 50ml salt solution 1.50, 9) 50ml salt solution 2.00 10) Scales, 11) Knife, 12) chopping board, 13) cork borer, Prediction & Theory: When the potato pieces are put in to the water there are more water molecules in the water then there is in the potato cells; therefore the water molecules move by osmosis into the potato cells through the membrane. This means that the mass of the potato piece will increase and the potato will feel harder. When the potato pieces are put in to the salt water there are more water molecules in the potato cells then in the salt water; therefore the water molecules by osmosis into the water from the potato. This means that the mass of the potato piece will decrease, and it will feel really soft. The stronger the concentration of the salt solution the more it will decrease in weight. Fair Testing: The things needed to be kept the same during this experiment to make it a fair test are: 1) The amount of each concentration must be 50ml. 2) There must be 3 pieces of potato in each concentration. 3) The same potato must be kept the same. 4) They all have to be left for the same amount of time. 5) They all have to be washed to get rid of the dead cells. Method: Making sure that there is a chopping board down cut with a cork borer 15 pieces of potato, but make sure that there isn't any holes and that you cut of the dead skin and that all the pieces are roughly the same size. In 5 pieces of potato put a pin at the top end, in another 5 pieces of potato put a pin in the middle, and leave the last 5 without out. This is done so that each piece is easier to identify when weighing. Weigh each piece of potato and make a note wether is has a pin in and what concentration it's going in to. Fill 5 beakers with the 5 solutions (see apparatus), and then put 3 pieces of potato one with the pin in 2006-02-16T03:25:59-05:00 http://75.150.148.189/free-essay/Investigating-Osmosis-In-Potato-Cells-28497.aspx The Biological Importance Of Water";"The Biological importance of Water Generally, the main biological importance of water is that life cannot exist without it. In fact on a percentage basis, the majority of any organism is comprised of water. Additionally, it is believed that life first originated in the bodies of water on the earth. The importance of water is seen in such third world countries as Kenya. Where the inhabitants are forced to drink water so dirty and contaminated that they know it might kill them. However they still drink it because it’s essential for life. The solvent properties of water are essential for living organisms to survive. The solubility of the substances needed by the organism depends on the ability of water to interact with them, and the polarity of water plays a critical role. Water is an excellent solvent for ionic compounds such as sodium chloride. This is because cations like sodium ions become surrounded by a shell of water molecules each attracted to the positive charge by the slight negative charge on the water-oxygen atoms. Anions are hydrated through the attraction of the slight positive charge of water-hydrogen atoms to their negative charge. Substances, inparticular polar substances, which dissociate in water, are known as hydrophilic. Covalent compounds are harder for water to act as the solvent. Some molecules have strong intramolecular forces, which prevent their solution in water, but have charged surfaces, which attract a covering of water molecules. This covering ensures that the molecules remain dispersed throughout the water, rather than forming large aggregates, which could settle out. The dispersed particles and liquid around them collectively form a colloid. Such substances are sugar and alcohols. This is important because such molecules provide an osmotic effect, which helps to draw water into the blood vessels of living organisms. The fact that water is a very effective solvent allows all of the substances essential for the functioning of cells and organisms (glucose, amino acids, vitamins, fats, respiratory gases) are transported around in solution in the blood. This means that water acts as a transport medium for the polar solutes. It carries things needed by cells to cells and products from cells to other cells and waste products to be excreted. In mammals this happens in the blood and in plants it happens in the xylem and phloem. Similarly all metabolic reactions, catalysed by enzymes occur in solution. Chemicals can only react with each other 2006-02-12T21:40:52-05:00 http://75.150.148.189/free-essay/The-Biological-Importance-Of-Water-28482.aspx Ribosomes What's most important? · Ribosomes are small dot-like structures in cells. · Ribosomes are often associated closely with endoplasmic reticulum(ER), forming rough ER. · Ribosomes are the site of protein synthesis in cells. Structure Ribosomes are made up of proteins and ribonucleic acid(RNA). These molecules are arranged into two subunits called the large and small subunits. These subunits are attached to each other and together form the entire ribosome. When viewed through a light microscope the ribosomes appear as dots, they are very small and the subunits can not be seen. Function The only function of ribosomes is to build proteins. The plan for the protein in the form of mRNA passes through a groove in the ribosome. The ribosome "reads" the plan and assembles the proper sequence of amino acids to build the protein. There are two kinds of ribosomes, those attached to the endoplasmic reticulum and those floating in the cell cytoplasm. Attached ribosomes make proteins that are used in the ER or transported within the ER. Free ribosomes make proteins that are used in the cytoplasm. The details of how ribosomes make proteins are presented in the "Protein Synthesis" section of your biology book. This is a complicated process beyond the scope of this document. Details Ribosomes are made in the nucleus of the cell. Ribosomes are about 60% rRNA by weight. A ribosome can make the average protein in about one minute. Ribosomes often line up in clusters called polyribosomes, these are connected by the mRNA and all make the same protein. In this way the cell can make many copies of a protein very fast. The cell or plasma membrane was once thought to be a simple barrier that kept the contents of the cell, the cytoplasm, contained. It serves as a gateway which helps to control materials going in and out of the cell. With more research, it turns out the cell membrane is very important in a wide range of cell activities including functions related to cancer and AIDS. Structurally, the membrane is a lipid bilayer. What this means is that, under the electron microscope two separate layers can be seen. The layers are composed of a two part molecule called a phospholipid. The lipids (fatty acids) are "water fearing" (hydrophobic) molecules. Just try to mix oil and water to see what that means. The phosphate end is water loving (hydrophilic). The membrane forms 2006-01-31T04:00:23-05:00 http://75.150.148.189/free-essay/6-Orgenels-Project-28464.aspx The Nitrogen Cycle The nitrogen cycle is a complex biological cycle involving the recycling of usable nitrogen. If this cycle ceased to occur, all forms of life on the planet would die. 2006-01-29T05:41:03-05:00 http://75.150.148.189/free-essay/The-Nitrogen-Cycle--28459.aspx Cro-Magnon report A cro-magnon is a early type of modern man named after the cro-magnon cave near Les Eyzies in the Dordogne,France, where four of the skeletons were discovered in 1868.Cro-magnons species grew in southern Europe during the last glacial age. The cro-magnons wore clothes and decorated their bodies with jewlery and ornaments of shell and bone. They were also skilled in carving and sculpturing with bone. IIn 1868 a fossil skull was discovered in the rock shelter of cro-magnon in southwestern France that can't be distinguished from a modern human skull.The tools that cro-magnons made were different from the tools made by neandertals and are connsidered to be more deep and advanced.A number of caverns in the Dordogne valley , Spain, Germany, and central Europe. Cro-magnon man was anatomically identical to modern humans, but differed significantly from Neandertals who disapeared in the fossil about 10,000 years after the appearance of Aurignacian and other paleothic populations. The abrupt disappearance of neanderthal populations and the assoicated mousterian technologies, the sudden appearance of modern Homo sapiens and the associated upper paleolithic technologies, and the absence of transitional anatomical or technologicalforms have led most researchers to conclude that Neanderthalswere driven to extinction through competition with cro magnons or related populations. The Homo sapiens were present during the end of the Ice Age, and were very adapted to living in this cold environment .They were short in stature averaging about 5'5" and had short arms and legs .This body shape helped to conserve heat. They also had an amazing projection in their nasal cavity thought to have provided more surface area for mucus to warm the cold frigid air before entering their bodies . Their brain was larger than modern humans, but it was longer and not as rounded . The Upper Paleolithic Period In the Upper Paleolithic period Neanderthal man disappears and is replaced by a variety of Homo sapiens such as Cro-Magnons . This, saw an astonishing number of human cultures, such as the Aurignacian, Gravettian, Perigordian, Solutrean, and Magdalenian, rise and develop in the Old World. The beginnings of communal hunting and extensive fishing are found here, as is the shelters, were built, sewn clothing was worn, and sculpture and painting originated. Tools were of great variety, including flint and obsidian blades and projectile points. It is probable that the people of the Aurignacian culture migrated to Europe after developing their distinctive culture elsewhere, perhaps in 2006-01-22T02:45:25-05:00 http://75.150.148.189/free-essay/Homo-Sapien-Development--28449.aspx Creation and Evolution are two major beliefs that people follow as a guideline. The two philosophies have different effects on our lives and the make up who we are and what we do. I will compare these two philosophies and show that they are totally opposite of each other and cannot go hand in hand. Creation is a belief followed by many people and the Holy Bible serves as a guideline and a set of instructions to show how the earth was formed and to guide us through life. Science backs up this Holy Book it is a very reliable source of the history of the world. Evolution cannot be clearly explained unless it is defined into two categories. Macro Evolution is one part of evolution, based on assumptions and beliefs. It is unscientific and has not been empirically proven. Macro Evolution states that life came from non-living materials and is slowly evolving from different kinds of species to better and stronger forms of life. Micro Evolution (adapting) is observable and has been scientifically proven many times, stating that different species adapt to their environment, but stay within their own species. The concept of Micro Evolution is totally unrelated with Macro Evolution and should not be tied in with evolution at all because people get confused in the two terms. When Evolution is mentioned throughout the paper, it is being referred to as Macro Evolution not Micro Evolution. There are many questions in life that man has always longed to find the answers to and the questions are: Who am I, why am I here, how did everything get here, and where will I go when I die? Well if you believe in evolution then you came from non-living material that all came together from the big bang. There is no purpose to life, you have no one to answer to, so if it feels good than do it and when you die then you will be recycled into a plant. We supposedly came here by chance through millions of years of evolving from a rock. In Creation, an all-powerful creator created you, life is a stepping-stone to get to heaven; there are consequences to what you do, rules to follow and someone to answer to. There is an afterlife for all people either heaven or hell, so lead a good life and 2005-10-27T23:31:35-04:00 http://75.150.148.189/free-essay/Evolution-vs_-Creation-28071.aspx Investigation On The Enzyme Trypsin An Investigation determining a factor affecting the rate of digestion of gelatin by the protease trypsin. Introduction An enzyme is a biological catalyst, which speeds up reactions. An example of this in the human body is trypsin (a protease produced in the pancreas and used in the stomach), which catalyses the digestion of gelatine, a protein. For this investigation, a photographic film will be the source of the gelatine. I will be able to identify when the gelatine is digested, when the photographic film turns from a dark brown colour, to being transparent. All enzymes are proteins, which are specific to the molecule that they break down. This is known as the ‘lock and key’ theory, where the active site only allows a specific substrate to be broken down, eventually resulting in easier absorption (larger surface area). Enzymes are made up of a long chain of amino acids, which form together in such a way as to leave a specific pocket, into which a substrate (as long as it fits perfectly into the pocket) can fit into it like a key in a lock (hence the ‘lock and key’ theory). The reaction then takes place, and the product of the substrate is then released. The enzyme, not changed by the reaction, can then perform the same “operation” on countless other substrates. Because the enzyme can be re-used, only a small amount is needed. Despite this enzymes can make cell reactions go many million times faster than they would normally. Since enzymes are biological catalysts, by definition, they are not used up or changed in the reaction that they catalyse. Even though they cannot be used up, when subjected to a high temperature (50°C and above), enzymes can become denatured and the active site damaged or destroyed. After denaturisation, the enzyme becomes useless as no more substrates can become further digested by them. Since there was ample trypsin for our use, and because trypsin begins to denature by 50°C (the temperature of the water bath I was using), I used a fresh batch of trypsin for each experiment I performed. Before I started, it was important for me to decide what factor I was going to set as my independent variable and what I was going to setting as my dependant variable. There were several possibilities. Since speeding up the reaction was obviously one option, I 2005-09-21T03:59:52-04:00 http://75.150.148.189/free-essay/Investigation-On-The-Enzyme-Trypsin-28016.aspx Animal Behavior Report Table of Contents Page 3: Aim and Hypothesis Page 4: Materials and Method Page 6: Critique of Data Page 7: Analysis of Data Page 8: Explanation in Terms of Theory Page 9: Conclusion Aim Animal behaviors develop as a result of the interaction between genetic and environmental influences. The purpose of this experiment is to imprint a chicken so it will think of you as its parent. Imprinting is the learning process observed in young birds and mammals, is the identification of an animal with another animal. Normally, it is a relationship between members of the same species, but it can occur, for example between a bird and a human, between members of different species. Imprinting can take place only during a particular period of the animal’s development – a specific time span, with chickens its hours after they hatch. Hypothesis Imprinting takes place during the early stages of development. By imprinting a baby chicken for two weeks, the chicken will see me as its ‘parent,’ and therefore respond to my movements. I will imprint the response to tapping and clucking. The chicken will follow my movements and as it becomes more accustomed to me, it will move quicker and without hesitation. Materials • Fish tank • News paper • Tea-towel • 2 small containers • lamp • chicken food/water • A3 paper and A4 paper • Shoe box Methods The Imprinting Process A. Initial Contact 1. Gently cup your hands around the animal and place it on a bench approximately 50cm in front of you. 2. Slowly release your hold on the animal ad gently withdraw your hands and draw them to your body. At the same time make soft clucking-type sounds. B. Reinforce Communication Bond 3. Repeat steps 1 and 2 until the animal keeps following your hands, 4. Cup the animal in your hands and hold it for approximately 10 to 15 seconds. 5. Keep repeating steps 1 to 3 for 15 to 20 minutes. 6. Place the animal back in the shoe box container and allow it to feed for approximately one hour 7. Repeat steps 1 to 3 for 15 to 20 minutes C. Final Imprinting of Animal 8. Gently place the animal on the floor. 9. Slowly and quietly move away from the animal and at the same time make soft clucking-type sounds. 10. Pick up the animal and gently cup it in your hands. 11. Repeat steps 8 2005-09-07T03:27:49-04:00 http://75.150.148.189/free-essay/Animal-Behaviour-Report--27942.aspx Cellular Transport Osmosis is the flow of water through a semi permeable membrane that blocks the transport of salts or other solutes through it. It is also defined as the net movement of water from an area of high concentration to a region of low concentration. Osmosis is a fundamental effect in all biological systems. When two water volumes are separated by a semi permeable membrane water will flow from the side of low solute concentration to the side of high solute concentration. If external pressure is applied on the area of high concentration then reverse osmosis may occur. The movement of solute molecules within a solvent is determined by the solvent molecules that surround it. Collisions of solute molecules determine movement. For example, in a u-tube, the two vessels are separated by a semi permeable membrane. The system will stabilize when the osmotic pressure is balanced. The solute molecules generate pressure on all solution boundaries, including the membrane. Osmosis is significant is plant and animal cells. In a plant cell, the water moves to the vacuole. In a hyperosmotic solution, that is, there is a lower concentration of water, if water permeates out of an animal cell, the cell becomes crenated or shriveled. In an isosmotic solution (equal concentrations) water enters and leaves the cell sufficiently, allowing the call to function properly. In a hypoosmotic solution (higher water concentration) the cell becomes lysed as too much water enters the call. When a plant cell is in a hyperosmotic solution, water leaves the cell and it becomes plasmolyzed. In an isosmotic solution, the flow of water in and out of the plant call is flaccid. In a hypoosmotic solution, the large amount of water that enters the cell causes to become turgid. Osmosis is a significant inn the functioning of cells. Another essential type of cellular transport is facilitated diffusion. Defined as the net movement of molecules, ions and atoms from a region of high concentration to low. All particles are constantly in motion, henceforth diffusion involves the movement of particles. Diffusion results from the random motion and/or collisions of particles. It is the act measured of particles as a result of a concentration gradient, where concentration is the number of particles per unit volume and concentration gradiet is a difference in concentration of a substance across a space. Diffusion will continue until the particles become uniformly distributed in the 2005-09-05T20:31:55-04:00 http://75.150.148.189/free-essay/Cellular-Transport--27896.aspx Basics Of Natural Selection Natural selection, or “survival of the fittest”, is an evolutionary shift in a species. It occurs when member or members of a species possess specific genetic traits (natural or a mutation) that are beneficial to their survival in a particular environment. Those that survive because of that trait are obviously the only left to reproduce and the trait carries over to their offspring, and becomes common to that species. This theory was observed by Darwin, and presented in his book “Origin of Species” published in 1859. The Darwin came upon this theory 20 years previous to the publication of his book during his travels on the Beagle. One stop on his journey was the Galapagos Islands. Darwin identified 13 species of finches in the Galapagos Islands. This puzzled him because he knew of only one species of this bird on the mainland of South America, 600 miles to the east, where they had all supposedly originated. He observed that the Galapagos species differed from each other in beak shape. He also noted that the beak varieties were associated with diets based on different foods. He concluded that when the original South American finches reached the islands, they dispersed to different environments where they had to adapt to different conditions. Over many generations, they changed anatomically in ways that allowed them to get enough food and survive to reproduce. His theory has also been tested in the laboratory. Controlled studies on male guppies have demonstrated natural selection at work. Those who had larger tails and had brighter coloration, more often females chose them as mates. Unfortunately, those same characteristics made them more vulnerable to predators. When the guppies were placed in a predator free environment, in just a few generations, the male guppies evolved brighter coloration and larger tails. When predators were reintroduced into the environment, the males went back the other way. They evolved smaller tails and less brilliant colors. One more example of natural selection was discovered in peppered moths living near industrialized English cities. They have varieties that vary in wing and body coloration from light to dark. During the 19th century, sooty smoke from coal burning furnaces killed the lichen on trees and darkened the bark. 2005-09-02T21:27:00-04:00 http://75.150.148.189/free-essay/Basics-Of-Natural-Selection-27866.aspx Importance of membranes in molecular transport and in ATP synthesis The way in which a membrane is assembled decides what is allowed in and out of a cell and how it advances through the cell membrane. Certain molecules can simply pass through the cell membrane through diffusion. Diffusion is a type of passive transport meaning no energy is used for the substance to enter or leave the cell. Another way for molecules to enter the cell is through facilitated diffusion. When a molecule is simply to large to diffuse through the cell membrane it can enter the cell through a Transport Protein. Facilitated diffusion is also a form of passive transport. When a molecule is to large to diffuse through the cell membrane it may enter the cell through the process of active transport. Active transport requires that a phosphate group such as ATP assist a Transport Protein. Exocytosis is another method for larger cells to penetrate the cell membrane and enter the cell. An object or objects are enclosed within a transport vesicle and then fuse to the plasma membrane thus releasing its contents. Endocytosis is just the opposite of exocytosis. In endocytosis the plasma membrane caves in and closes off the molecules inside itself and then pinches itself away from the plasma membrane and into the cell. Three types of endocytosis are phagocytosis where the cell consumes the molecule, pinocytosis where the cell drinks the molecules, and receptor-mediated endocytosis where the membrane forms a pit and pinches closed with the needed molecules inside. The stomata are microscopic pores bordered by guard cells in the epidermis of leaves that allows carbon dioxide to be exchanged between the environment and the interior and oxygen to exit out of the leaf and plant. The carbon dioxide then goes to the Tylakoids, flattened membrane sacs inside the chloroplast they are used to change light energy to chemical energy. The membrane that is most involved in the synthesis of ATP in photosynthesis is the thylakoid membrane. Inside the thylakoid membrane are both of the photosystems and both the electron transport chains and ATP synthase. Starting in photosystem II excited electrons from water travel along the first E.T.C., a four-protein electron transport chain, allowing H+ ions to travel from one side of the membrane to the other. 2005-08-28T06:33:21-04:00 http://75.150.148.189/free-essay/Importance-of-Membranes-in-Molecular-Transport,-ATP-Systems-27800.aspx Photosynthesis - Changing Carbon Dioxide and Water to Sugars 6H2O + 6CO2 C6H12O6+ 6O2 Six molecules of water plus six molecules of carbon dioxide produce one molecule of sugar plus six molecules of oxygen Photosynthesis is the process that green plants and certain other organisms use to change carbon dioxide and water into glucose (sugar) using the suns energy. Photosynthesis provides the basic energy source for practically all living organisms. A very important byproduct of photosynthesis is oxygen, which we can’t live without. Photosynthesis occurs in green plants, seaweeds, algae, and certain bacteria. These organisms are major sugar factories, producing millions of new glucose molecules per second. Plants use the glucose, a carbohydrate, as a source of energy to grow leaves, flowers, fruits, and seeds. They also change glucose to cellulose, the structural material used in their cell walls. Most plants produce more glucose than they use so it gets stored in the form of starch and other carbohydrates in their roots, stems, and leaves. The plants can use the stored starch later to help them grow. Plants are the only photosynthetic organisms to have leaves (not all plants have leaves). A leaf is a major solar collector crammed full of photosynthetic cells. The water and carbon dioxide come into the cells of the leaf, and the products of photosynthesis, sugar and oxygen, leave the leaf. Water enters the root and is moved up to the leaves through cells known as xylem. Land plants can dry out fast so they have a special opening called a stomata, this lets gas in and out of the leaf. Carbon dioxide cannot pass through the protective waxy layer covering the leaf (cuticle), but it can enter the leaf through the stomata. Oxygen that is produced during photosynthesis can only pass out of the leaf through the opened stomata. Humans and other animals depend on glucose as an energy source, but they can’t make it on their own so they must rely on the glucose produced by plants. The oxygen that humans and animals breathe is the oxygen released during photosynthesis. Humans also depend on ancient products of photosynthesis, known as fossil fuels. Without fossil fuels we wouldn’t have natural gas, coal or petroleum. Fossil fuels are made up of 2005-08-21T08:11:55-04:00 http://75.150.148.189/free-essay/Photosynthesis-Changing-Carbon-Dioxide-and-Water-to-Sugars-27761.aspx About Piranha's, Having a Piranha as a Pet Did you know that there are at least twenty-five different kinds of piranhas? Most have deep flat bodies, range in color from olive green to blue black, and have red orange bellies. The most dangerous of the species have large very sharp teeth, the upper and lower set which fit perfectly together. These remarkable fishes have other characteristics which enhance their biting ability. Their lower jaws are sturdy and they swing shut at an angle that gives maximum leverage. Their deep flat bodies which offer resistance when swung sideways through the water add to the leverage. Incredibly large muscles are attached to the jaws. The muscles are so sturdy that when you that when you look down a large specimens throat it barely looks like enough room to swallow. When the fish clamps down on a victim it grabs firmly and twists its body violently until a piece is torn loose. In a word, the piranha is the most efficient biting machine. Every body part seems to make a contribution to this function. Fishing for the piranha in the Guyanas upper Abary River can be very exciting but very dangerous. The author of Unusual Aquarium Fishes, Alan Mark Fletcher, was using special heavy shanked steel fish hooks and twice piranhas bit completely through the strong fish hooks. A man with a pair of pliers would have a hard time snipping through the heavy shanked hooks. This author has taken many daring risks such as having himself photographed holding a live piranha in the exact spot where it had just been caught. While in some places the piranha are extremely dangerous, in others its quite harmless most of the time. In the upper Amazon River, Indian children swim and play in the waters that teems with the fish. Yet in Guyanas Abary River one takes a great risk to place his hands in the water. Some species of the piranha family, called the Candiru, attach themselves by means of suction, for which their mouths are adapted. They fasten themselves on their victim and then painlessly cut the skin and gorge themselves in its blood. Any of the fish brought to the market at Manaos often show many wounds inflicted by the piranha. Below the first fall in the Maderia River, it is difficult to take a catfish which has 2005-08-18T09:32:25-04:00 http://75.150.148.189/free-essay/Personal-Animal-Research-Paper-Piranha-27727.aspx Jay Gould’s essay "Natural selection and the human brain," an argument for evolution It has been over 100 years since English naturalist Charles Darwin first told the world his revolutionary concept about how livings things develop. Evolution through natural selection and adaptation was the basis of his argument as it remains to this day a debated subject by many. Across this nation, a "return" to "traditional" values has also brought the return of age old debated topics. One issue that truly separates Americans is the issue of creation versus evolution. Since the 19th century, this divisive topic has been debated in school boards and state capitols across America. In many instances religious fundamentalists won the day by having banned the instruction or even the mention of "ungodly" evolutionary thinking in schools. With today's social and political climate, this question is back with greater force than ever. This is why this subject is more important now than ever. In Jay Gould's book The Panda's Thumb, an overview of and an argument for Charles Darwin's evolutionary thinking is conducted with flowing thoughts and ideas. This essay titled "Natural Selection and the Human Brain: Darwin vs. Wallace" takes a look directly at two hard fought battles between evolutionists and creationists. Using sexual selection and the origins of human intellect as his proponents, Gould argues his opinion in the favor of evolutionary thought. In this essay titled "Natural Selection and The Human Brain: Darwin vs. Wallace," Gould tells about the contest between Darwin and another prominent scientist named Alfred Wallace over two important subjects. These topics, one being sexual selection and the other about the origins of the human brain and intellect were debated by men who generally held the same views on evolution. However on these two subjects, Wallace chose to differ as he described it as his "special heresy" (53). The first of these two areas of debate between the two men was the question of "sexual selection." Darwin theorized that there laid two types of sexual selection. First a competition between males for access to females and second the choice "exercised by females themselves" (51). In this, Darwin attributed racial differences among modern human beings to sexual selection "based upon different criteria of beauty that arose among various peoples" (51). Wallace, however, disputed the suggestion of female choice. He believed that animals were highly evolved and beautiful works of art, not allowing 2005-08-15T08:58:37-04:00 http://75.150.148.189/free-essay/Jay-Gould-Natural-Selection-and-the-Human-Brain-27689.aspx Cricket deterrents lab experiment, science project Insects have been a nuisance to man since the beginning of time, up until the present. One of the plagues that struck Egypt was swarms of crickets, and locusts, which destroyed crops, and ate entire fields. Swarms of Crickets can cover up to 210 km. There have been cases of up to 100,000,000,000 insects in a swarm (one hundred billion). In these huge masses, they can completely destroy the land and everything on a farm. I chose to do this experiment because when I am at camp I am constantly woken up by the loud chirping of these annoying insects. There are three types of crickets: Mole Crickets, Field Crickets, and House Crickets. The Mole Cricket’s body is designed for digging subterranean tunnels. This Cricket’s body is well adapted to digging. The Mole Cricket usually lives in hot dry areas, and are extremely harmful to plants such as barley, and flax The Field Cricket has had a history in ancient China. This cricket’s beautiful song was held in particularly high esteem. These crickets were often kept in exquisitely ornamented cages made of sandalwood, ivory or jade. The Most common cricket is the house cricket. The house cricket’s body is more slender than that of the field cricket. It is also generally lighter in color. This crickets appears in abundance in central Europe, such as cellars, houses, bakeries, and so on. Procedure Problem: How do I make a cricket deterrent that is environmentally friendly? Hypothesis: If I use a deterrent that has a strong odor, then it will deter the crickets from that area. I started my experiment by first buying 60 crickets. The crickets were stored in bags until they were ready to be used. I purchased a clear plastic box with holes in the top for breathing. I made a divider out of cardboard and secured it in the center of the box, making four equal sections. One section was the control, and in the others I put a deterrent. Two tests were made that were thrown out because they were irrelevant. In the first case, the crickets were not deterred at all by any of the substances. The test was done outside, and the crickets seemed to simply move their position depending on the location 2005-08-15T08:55:56-04:00 http://75.150.148.189/free-essay/Cricket-Deterrents-Lab-Experiment-Science-Project-27687.aspx Nature vs. Nurture Debate There is an issue that has been conferred upon by philosophers in the past and still so by scientists today. This issue is whether heredity or environment plays a greater role in the determining or shaping of an individual's behavior. It is known as the nature versus nurture debate. Numerous generations before us have deliberated on the reasons behind the development of human behavior. There have been many theories formulated to explain why humans behave the way they do. The surviving theories for behavior derive from physiological and sociological explanations. However, the two explanations have not always been compatible with each other. The famous nature vs. nurture debate over human behavior resulted from conflicting views between proponents of the physiological (nature) and sociological (nurture) explanations. Throughout history, research has swayed popularity back and forth between the theories. Yet, theorists have broken down the line separating nature and nurture. As of today, people utilize both explanations to explore human behavior. Way before our time, early philosophers endeavored to understand the human behavior. As early as 350 BC, such philosophers as Plato and Aristotle tried to understand behavior. The question of nature or nurture as the primary drive can be traced to these times. Plato believed behavior and knowledge was due to innate factors. Author Fiona Cowie states, "The claim that the character of our mental furniture is to a large extent internally rather than environmentally determined found its first substantive defense in the works of Plato..." (Cowie, 1999). Plato theorized that all knowledge is present at birth. Plato also believed that the environment played a part in human processes, but he thought it had an unique role. He believed the environment did not teach people anything new, but its purpose was to remind people of information they already knew (Cowie, 1999). Although Plato's views are not supported today, he laid the groundwork for other researchers to follow. Alternatively, philosopher Aristotle theorized a different idea about human behavior. He presented the idea that humans are born into the world with a "blank slate" and people's behavior and thoughts are due to experience (Ashcraft, 1998). Unlike Plato, Aristotle hypothesized that humans were not born with knowledge, but they acquire it through experience (Ashcraft, 1998). Aristotle's idea of the tabula rasa is not believed today. Nevertheless, his belief that the environment was a vital factor in behavior influenced many empiricists throughout 2005-08-05T05:26:30-04:00 http://75.150.148.189/free-essay/Nature-versus-Nurture-Debate-27567.aspx The Entire Process of Photosynthesis Photosynthesis is the process by which organisms that contain the pigment chlorophyll convert light energy into chemical energy which can be stored in the molecular bonds of organic molecules. Photosynthesis powers almost all trophic chains and food webs on the Earth. The net process of photosynthesis is described by the following equation: 6CO2 + 6H2O + Light Energy = C6H12O6 + 6O2 This equation simply means that carbon dioxide from the air and water combine in the presence of sunlight to form sugars; oxygen is released as a by-product of this reaction. Photosynthesis begins when light strikes Photosystem I pigments and excites their electrons. The energy passes rapidly from molecule to molecule until it reaches a special chlorophyll molecule called P700, so named because it absorbs light in the red region of the spectrum at wavelengths of 700 nanometers. Until this point, only energy has moved from molecule to molecule; now electrons themselves transfer between molecules. P700 uses the energy of the excited electrons to boost its own electrons to an energy level that enables an adjoining electron acceptor molecule to capture them. The electrons are then passed down a chain of carrier molecules, called an electron transport chain. The electrons are passed from one carrier molecule to another in a downhill direction, like individuals in a bucket brigade passing water from the top of a hill to the bottom. Each electron carrier is at a lower energy level than the one before it, and the result is that electrons release energy as they move down the chain. At the end of the electron transport chain lies the molecule nicotine adenine dinucleotide (NADP+). Using the energy released by the flow of electrons, two electrons from the electron transport chain combine with a hydrogen ion and NADP+ to form NADPH. When P700 transfers its electrons to the electron acceptor, it becomes deficient in electrons. Before it can function again, it must be replenished with new electrons. Photosystem II accomplishes this task. As in Photosystem I, light energy activates electrons of the Photosystem II pigments. These pigments transfer the energy of their excited electrons to a special Photosystem II chlorophyll molecule, P680, that absorbs light best in the red region at 680 nanometers. Just as in Photosystem I, energy is transferred among pigment molecules and is then directed to the P680 chlorophyll, where the energy is used to 2005-08-02T13:07:22-04:00 http://75.150.148.189/free-essay/Entire-Process-of-Photosynthesis-27530.aspx Understanding Chromosomes Imagine... you are in charge of building a 200-story skyscraper. The skyscraper has all of the newest technological features, and production has to start tomorrow. Would it happen? Of course not, you would need blue prints. This goes with your body, too. When you are born, your body has to know where everything has to go. You know, a muscle cell goes to your biceps; a (fried) brain cell goes up in to the attic. That is what chromosomes are. I am going to talk about chromosomes. They are your genetic blueprints, DNA and how you can extract DNA from anything that was living. Chromosomes are your hereditary blueprints. These blueprints tell your body what color eyes you will have. These chromosomes tell your body where every thing goes in your body. This instruction set is know as DNA, which I will explain about in the next paragraph. There are pairs of 23 chromosomes in all of the cells in your body. Making a total of 46 chromosomes. Two of those chromosomes tell whether you are going to be a male of female. These are the X and Y-chromosomes. If some one has two X chromosomes then she will be a female. If there is an X and a Y chromosome then he will be a boy. Secondly I will tell you about the DNA contained in the chromosomes. DNA stands for deoxyribonucleic acid. DNA is the blue print for the human we are going to build. This DNA is tightly wrapped around proteins. If this DNA were not tightly wrapped around proteins then the strand of DNA would be much too large to fit in a cell’s nucleus. The double helix shaped DNA would be about 2 inches long. That two inch long, skinny strand of DNA contains all of the information we need to build our very own human. Now how are we going to build our very own human? Well, that is (kind of) simple. We use RNA. RNA stands for ribonucleic acid. In simple terms, RNA builds the human really wanted. Now I bet you are thinking I wish I could get my very own DNA, but that will cost a lot of money… well you are wrong. Stay tuned and I will tell you how… Now I am going to tell you how to extract DNA from anything living. There are 5 simple steps, and 2005-08-02T06:27:52-04:00 http://75.150.148.189/free-essay/Understanding-Chromosomes-27526.aspx Development of the Human Zygote, Human Reproduction Essay November 16, 1995 Hundreds of thousands of times a year a single-celled zygote, smaller than a grain of sand, transforms into an amazingly complex network of cells, a newborn infant. Through cellular differentiation and growth, this process is completed with precision time and time again, but very rarely a mistake in the 'blueprint' of growth and development does occur. Following is a description of how the pathways of this intricate web are followed and the mistakes which happen when they are not. The impressive process of differentiation changes a single-cell into a complicated system of cells as distinct as bold and bone. Although embryonic development takes approximately nine months, the greatest amount of cellular differentiation takes place during the first eight weeks of pregnancy. This period is called embryogenesis. During the first week after fertilization, which takes place in the Fallopian tube, the embryo starts to cleave once every twenty-four hours (Fig. 1). Until the eight or sixteen cell stage, the individual cells, or blastomeres, are thought to have the potential to form any part of the fetus (Leese, Conaghan, Martin, and Hardy, April 1993). As the blastomeres continue to divide, a solid ball of cells develops to form the morula (Fig. 1). The accumulation of fluid inside the morula, transforms it into a hollow sphere called a blastula, which implants itself into the inner lining of the uterus, the endometrium (Fig. 1). The inner mass of the blastula will produce the embryo, while the outer layer of cells will form the trophoblast, which eventually will provide nourishment to the ovum (Pritchard, MacDonald, and Gant, 1985). Figure 1:Implantation process and development during embryogenesis (Pritchard, MacDonald and Gant, 1985) During the second week of development, gastrulation, the process by which the germ layers are formed, begins to occur. The inner cell mass, now called the embryonic disc, differentiates into a thick plate of ectoderm and an underlying layer of endoderm. This cellular multiplication in the embryonic disc marks the beginning of a thickening in the midline that is called the primitive streak. Cells spread out laterally from the primitive streak between the ectoderm and the endoderm to form the mesoderm. These three germ layers, which 2005-08-01T07:25:50-04:00 http://75.150.148.189/free-essay/Development-of-the-Human-Zygote-27504.aspx Diabetes Mellitus Research Essay Abstract Diabetes is a disease that affects 18.2 million people in the United States alone. This disease results when there is a high level of sugar in the blood for an extended period of time. It can be controlled by diet, exercise, pills and insulin injections. There are three main types of diabetes--Type I, which affects primarily the younger population; Type II, which primarily affects the population above 40; and gestational diabetes, which affects women during the third trimester of their pregnancy. While scientists do not know what causes diabetes, they do know that it is caused from a variety of factors that can vary from person to person. Examples of these factors are heredity, being overweight, and problems with beta cells, which are located in the pancreas. Diabetes can result in blurred vision, retinopathy, nerve problems, dry skin, and kidney issues. Diet plays a major role in the prevention of these problems. Sugar concentration in the blood is a major factor for diabetics, so understanding the sugar content of fats, proteins, and carbohydrates is essential. The goal from a diet perspective is to control your sugar in your bloodstream in such a way that the insulin in your bloodstream can manage it efficiently. In addition to diet, medication and exercise play a key role in controlling this disease. Currently, there is no known cure for diabetes. Diabetes Mellitus Diabetes Defined Diabetes Mellitus is a chronic disease where the blood in the body contains a high sugar level. This disease is caused by the body's inability to use insulin properly, or the inability to manufacture insulin altogether. There are times when it can be caused by both factors. "Diabetes is the leading cause of blindness, kidney failure, and leg amputations. In fact, it is the third leading cause of death in the United States." (Magee, 1999 p. 2) The Normal Process When you eat a meal, your body begins the digestion process. The food breaks down and enters the bloodstream in the form of sugars. Once the sugars are circulating in your blood, the cells need to be able to admit the sugar. A hormone called insulin is the factor that makes this possible. Once the insulin lets the sugar into the cells, it is used to produce energy. The Failure Taking insulin out of the equation, the cells in your body cannot use sugar as they would normally. Consequently, they do not get enough 2005-08-01T07:24:01-04:00 http://75.150.148.189/free-essay/Research-Paper-on-Diabetes-Mellitus-27503.aspx [i:d871a2816b]Explain how homopoiesis occurs and how it results in mature red blood cells. How are other formed elements in blood made? Explain how homopoiesis is regulated by negative feedback mechanism. Describe three conditions, which would interfere with this and result in anemias.[/i:d871a2816b] The process of homopoiesis takes place in the red bone marrow, which is a soft network of reticular connective tissue that borders on wide blood capillaries called sinusoids. In this network are immature blood cells, macrophages, fat cells, and reticular cells (the fibroblasts that secrete the fibers). Each type of blood cell is produced at different rates, according to the body's changing needs. All formed elements of blood begin as the same type of stem cell, the hematopoietic stem cell. The appearance of membrane surface receptors, which respond to different hormones, are what determine which type of formed element a stem cell will become. RBC production (erythropoiesis) starts when a hemocytoblast known as a myeloid stem cell that becomes a proerythroblast. These then become early (basophilic) erythroblasts that produce millions of ribosomes. In these first two phases, the cells divide many times. Hemoglobin synthesis and iron accumulation occur while the early erythroblast becomes a late erythroblast and then a normoblast. It's cytoplasm color changes as the blue staining ribosomes are masked by the pink color of hemoglobin. When the normoblast gains a hemoglobin concentration of about 34% the cell collapses inward and gains its biconcave shape. It is now a reticulocyte (young erythrocyte) because it still contains a slight network of clumped ribosomes and rough endoplasmic reticulum. The whole process from hemocytoblast to reticulocyte takes 3-5 days. Now, filled almost to bursting with hemoglobin, the mature cells diffuse through the sinusoids and enter the bloodstream and begin oxygen transport. They usually become mature erythrocytes within two days of release due to their ribosomes being destroyed by intracellular enzymes. Hence, the mature erythrocyte or RBC! Reticulocytes usually account for 1-2% of all erythrocytes in healthy people. Keeping a reticulocyte count is a clinical way to monitor normal vs. abnormal erythrocyte formation. The negative feedback mechanism has a stimulus that could be a pregnancy (fetal Hb) or high altitude. When kidney cells don't have enough oxygen available they release erythropoietin. Erythropoietin stimulates red bone marrow and increases red blood cell count. This increases the oxygen carrying ability of blood. Recycling of red blood cells occurs largely in the spleen, which is made up 2005-08-01T07:21:54-04:00 http://75.150.148.189/free-essay/Essay-on-the-Process-of-Homopoiesis-27502.aspx To understand the process of DNA replication, you much first be familiar with the structure of DNA. Resembling a twisted ladder, DNA is a double helix formed with nucleotides, a phosphate and sugar backbone, and nitrogenous bases. There are four bases, and each one will only bond with it’s complement. Adenine will only bond with Thymine, and Cytosine with only Guanine. The double helix is antiparallel, meaning each strand runs in a different direction. The first step to DNA replication is the unwinding of the double helix with the help of an enyme called helicase. Once unwound, the DNA unzips and the bonded nucleotides 2005-07-26T04:53:23-04:00 http://75.150.148.189/free-essay/DNA-Replication--27381.aspx Neurological Regeneration Biological regeneration has been studied over the years, in salamanders, and biological imitations of life. Through research on the mitotic capabilities of certain animals, to the DNA and hormones that make regeneration possible, scientists are slowly finding a way so that humans can regenerate lost or missing limbs, or grow organs used to save millions of lives in the future. Because being able to reproduce a limb or body part is dependent on nerves, scientists have found it vital to perform especial experimental procedures to find a way to prevent difficult regenerated nerves from inhibiting the regeneration process. The medicinal leech, a worm-like creature once used by doctors to bleed patients, now is being used to draw clues on how a common protein may help promote neural regeneration. A specific enzyme or protein, called nitric oxide synthase, or NOS, is activated when parts of the nerve cell are damaged in the medicinal leech. This particular Hirudinean leech is a three-inch-long invertebrate known for its ability to regenerate its neural connections. Scientists hope that one day their findings may be applied to research in human spinal regeneration. Purdue's studies show that NOS in the leech is activated at the site of injury within minutes after axons or nerves are severed. Axons are the long "arms" of a nerve cell that carry impulses away from the cell body toward a target cell. NOS remains active well beyond 48 hours after the injury to start neural reconstruction. Conducting follow-up studies to identify what information this molecule provides at a cellular level, they see how these functions might help the leech's nervous system set itself up to allow regeneration to occur. This same enzyme NOS, also found in humans, produces a "signaling" molecule that sends chemical messages throughout the body to incite certain chemical reactions. The enzyme found in leeches is very much like the human NOS, and it may serve a similar function in both species. However, the drawback is that nerve regeneration in higher systems is not complete as it is in medicinal leeches and such less complex creatures. By analyzing how nerves regenerate in a simple system, scientists may begin to find clues to facilitate regeneration in vertebrates. After the problems of regeneration and axonal regrowth are solved for humans, the next issue scientists are interested in, is the creation of man-made tissues or organs, known as neo-organs. There are 2005-07-16T07:46:06-04:00 http://75.150.148.189/free-essay/Neurological-Regeneration-Debate-27307.aspx Neurological Regeneration Biological regeneration has been studied over the years, in salamanders, and biological imitations of life. Through research on the mitotic capabilities of certain animals, to the DNA and hormones that make regeneration possible, scientists are slowly finding a way so that humans can regenerate lost or missing limbs, or grow organs used to save millions of lives in the future. Because being able to reproduce a limb or body part is dependent on nerves, scientists have found it vital to perform especial experimental procedures to find a way to prevent difficult regenerated nerves from inhibiting the regeneration process. The medicinal leech, a worm-like creature once used by doctors to bleed patients, now is being used to draw clues on how a common protein may help promote neural regeneration. A specific enzyme or protein, called nitric oxide synthase, or NOS, is activated when parts of the nerve cell are damaged in the medicinal leech. This particular Hirudinean leech is a three-inch-long invertebrate known for its ability to regenerate its neural connections. Scientists hope that one day their findings may be applied to research in human spinal regeneration. Purdue's studies show that NOS in the leech is activated at the site of injury within minutes after axons or nerves are severed. Axons are the long "arms" of a nerve cell that carry impulses away from the cell body toward a target cell. NOS remains active well beyond 48 hours after the injury to start neural reconstruction. Conducting follow-up studies to identify what information this molecule provides at a cellular level, they see how these functions might help the leech's nervous system set itself up to allow regeneration to occur. This same enzyme NOS, also found in humans, produces a "signaling" molecule that sends chemical messages throughout the body to incite certain chemical reactions. The enzyme found in leeches is very much like the human NOS, and it may serve a similar function in both species. However, the drawback is that nerve regeneration in higher systems is not complete as it is in medicinal leeches and such less complex creatures. By analyzing how nerves regenerate in a simple system, scientists may begin to find clues to facilitate regeneration in vertebrates. After the problems of regeneration and axonal regrowth are solved for humans, the next issue scientists are interested in, is the creation of man-made tissues or organs, known as neo-organs. There are 2005-07-04T18:20:15-04:00 http://75.150.148.189/free-essay/Neurological-Regeneration-27249.aspx Geneticall Engineered Golden Rice At one time, golden rice was just a wild idea that Ingo Potrykus thought up. Optimally, golden rice would improve the lives of millions of the poorest people in the world. The rice would contain beta-carotene which is the building block for vitamin A. However, imagining golden rice was one thing and bringing it into existence was another. He struggled for years with his colleagues to deal with the finicky growing habits of the rice they transplanted to a greenhouse near the foot hills of the Swiss Alps. Potrykus and his colleagues became successful in the spring of 1999. By creating golden rice, Potrykus wanted to be sure it would reach malnourished children of the developing world; those for whom it was intended. He knew that would not be easy because of the fact that the golden grains also contained snippets of DNA borrowed from bacteria and daffodils. Being a product of genetical engineering, Potrykus's product was entangled in a web of hopes, fears, and political baggage. Until now, genetically engineered crops were created to resist insect pests or to control the growth of weeds by using herbicides. However, in this circumstance the genetically engineered rice not only benefits the farmers who grow it, but primarily the consumers who eat it. These consumers include at least a million children who die every year because they are weakened by vitamin-A deficiency and an additional 350,000 people who go blind. In addition to this concern, there is another. It is prospected that by the year 2020, the demand for grain, both for human consumption and for animal feed, is projected to go up by nearly half, while the amount of farmable land will probably dwindle, thus introducing a whole new series of problems. There is only a short four step process that enables one to produce golden rice. The genes that give golden rice is its ability to make beta-carotene in its endosperm come from daffodils and a bacterium called Erwinia uredovora. These genes, along with promoters (segments of DNA that activate genes), are inserted into plasmids that occur inside a species of bacterium known as Agrobacterium tumefaciens. These agrobacteria are then added to a Petri dish containing rice embryos. As they "infect" the embryos, they also transfer the genes that encode the instructions 2005-07-03T05:03:26-04:00 http://75.150.148.189/free-essay/Geneticall-Engineered-Golden-Rice-27218.aspx Genetic Engineering. Right or Wrong? Genetic engineering has been one of the most controversial ethical issues since 1997; when Dolly the first successfully cloned sheep was announced. Dolly has redefined the meaning of "identical twin"; not only does she look exactly like her mother she also has the same genetic make up. This experiment was not only impossible but unthinkable. Yet, Dr. Ian Wilmut revealed Dolly on February 23, 1997, at seven months old ( Travis 1). On the surface genetic engineering may appear to be the solution to all of society's ills and the worlds problems. In all actuality it may have tremendous and unknown side effects. The issues that surround genetic engineering undoubtedly make it immoral and ethically wrong. Genetic Engineering as defined by Susan A. Hagedorn is: The manipulation of an organism's genetic endowment by introducing or eliminating genes through modern molecular biology techniques. A broad definition of genetic engineering also includes selective breeding and other means of artificial selection ( "Genetic Engineering" 1). After hearing of the "creation" of Dolly Americans soon learned the harsh fact surrounding her creation. Dr. Wilmut's success was accompanied by 276 failures. This success rate is no where near clinically acceptable. To start the developing of the eggs they were shocked with electric pulses; twenty nine of the 277 of these eggs began to divide. The eggs, at that point were implanted into adult female sheep; thirteen of which became pregnant, and only the one of 277 eggs were born - Dolly ( Wilmut 1). Long term prospects of mammal cloning remain in question. This is not clinically acceptable for experimentation on humans. In the months following the news of Dolly, President Clinton requested, "a through review of the legal and ethical issues associated with the use of this technology... with recommendations on possible federal actions to prevent its abuse" (Shermer 1). The answer is clear-- there is no safe place to draw the line on when genetic engineering is acceptable and is not. Governments can not say that the uses are strictly limited to curing disease because then there becomes a question of what is a genetic disease. For example, we may feel comfortable defining a mutation in the cystic fibrosis gene as causing disease if it leads to chronic respiratory infections from birth to death at the age 2005-06-30T05:04:02-04:00 http://75.150.148.189/free-essay/Genetic-Engineering_-Right-or-Wrong-27203.aspx Biology Research Paper: In Vitro Fertilization. In Vitro Fertilization (IVF), is the procedure whereby human babies are conceived, not in the womb but in a test tube or a Petri dish. This procedure has become one of the greatest developments in the world of medical technology. In Vitro Fertilization has given infertile couples the chance to conceive and bear a child from a full term of pregnancy. Without this procedure, their infertility would render them childless. There are many aspects of the IVF program that have been both praised and criticized. The legal, ethical and social repercussions of the IVF program have created great debate and controversy. This essay will demonstrate the procedures used in the IVF program and set out the arguments for and against it. There are many reasons why couples cannot conceive or bear a child for a full term of pregnancy. The process of natural fertilization can only be achieved if the male and female reproductive organs are functioning without any abnormalities. The reproduction process begins with the male producing sperm in the testes and the female producing an egg in the ovaries. Once every 28 days or so, an egg matures in the ovary, bursts from its follicle and enters the Fallopian tube. Once sexual intercourse has taken place, millions of sperm released from the penis swim up the vagina, through the uterus and into the Fallopian tube. 'A single sperm fertilizes the egg; the others are locked out.' (Time, 1997, pg. 66) Once the egg has been fertilized, cell division begins and the embryo drifts down the Fallopian tube. The embryo reaches the uterus in about a week. The embryo anchors itself to the wall of the uterus where it develops into a foetus. The foetus feeds off nutrients and oxygen provided by the placental lining in the uterus. There are several conditions in both males and females that cause abnormalities in the functioning of natural fertilization. Firstly, a condition in women called Endometriosis causes infertility. 'It is a condition where pieces of uterine tissue leak out of the uterus into the Fallopian tube.'(Fertility Rights, 1993, pg. 6) It causes blockages in the Fallopian tubes and 'is associated with infertility even when the Fallopian tubes are not actually blocked.' (Fertility Rights, 1993, pg6) Secondly, the cause of infertility in men is a reduced sperm count, or low 2005-06-21T22:33:17-04:00 http://75.150.148.189/free-essay/Biology-Research-Paper-In-Vitro-Fertilization-27117.aspx Excess dietary protein and Hypercalcuria. Calcium INTRODUCTION: Osteoporosis is the major public health problem in the United States because the disease costs million lives and dollars. Osteoporosis, which means "porous bones," is a condition of excessive skeletal fragility resulting in bones that break easily. A combination of genetic, dietary, hormonal, age-related, and lifestyle factors all contribute to this condition. Osteoporosis leads to 1.5 million fractures, or breaks, per year, mostly in the hip, spine and wrist, with the cost of treatment estimated at $10 billion to $15 billion a year, according to the National Institutes of Health. It threatens 25 million Americans, mostly older women and men. One in three women past 50 will suffer a vertebral fracture, according to the foundation (Munger 147). These numbers are predicted to rise as the population ages. Most causes of osteoporosis are uncontrollable, such as genetics and ages. However, there are also dietary factors and living lifestyles that contribute greatly to the disease. For more than half a century there were studies and research, which showed that that diets high in protein increase calcium resorption from bone and urinary calcium excretion, thus, increasing the risks for osteoporosis and other diseases (Munger 149-52). First, this paper will give evidences about how diets that are high in protein contents can cause hypercalciuria. Second, it will give the mechanism of how hypercalciuria is caused. Lastly, it will present what types of people are affected by this disease, and how diets high in fruit and vegetables can reverse the process. THE EVIDENCES: There were many researches and studies, which proved that high consumption of dietary protein could lead t urinary calcium excretion, and eventually caused hypercalciuria. One of those evidences was a study conducted by Dr. Jane Kerstetter at the School of Allied Health. His study concluded that high levels of dietary protein increased urinary calcium excretion and induced negative calcium balance. The experiment had sixteen healthy women (aged 20-40 yr) as participants. The control was a two-week diet containing moderate amounts of calcium, sodium, and protein. Followed the control was the experimental diet, which was four days long and consisted of one of three levels of protein (low, moderate, or high). On day four, serum and urinary calcium, serum PTH, 1,25-dihydroxyvitamin D, serum osteocalcin, bone-specific alkaline phosphatase, and urinary N-telopeptide excretion were measured (Kerstetter 1053-4). The cycle of a 2-week adjustment period and a 4-day experimental period was repeated two 2005-06-21T22:02:52-04:00 http://75.150.148.189/free-essay/Excess-Dietary-Protein-and-Hypercalcuria_-Calcium-27094.aspx The neuromuscular junction as a site of disease process Proteins involved in formation of the neuromuscular junction The neuromuscular junction is a specialized junction, where a motor nerve forms its synaptic terminal with a muscle fibre, one of many fibres that make up a whole muscle. The mature neuromuscular junction is composed of three types of cells - a motor nerve terminal, a muscle fibre and a Schwann cell covering the junction. All three of these cells are highly differentiated and specialized for their functions (Kandel 2000, p. 1089). The events that occur during the formation of the neuromuscular junction have been extensively studied and are the most comprehensively understood of any nerve-to-target cell contact. Prior to formation of the synapse all three components of the neuromuscular junction develop and acquire identities independently. The muscle cells are derived from the mesoderm and migrate from the dermomyotomal portion of the somite. Motoneurons migrate from the ventricular zone of the neural tube to a ventral-lateral location before axons grow out of the spinal cord. Schwann cells are glial cells, which insulate the axons outside of the spinal cord, they are derived from neural crest cells and associate with axons from the somite onwards to the peripheral target. At the time of the first axons reaching the developing muscle, the muscle fibres are myoblasts that have just fused to form multinucleated myotubes, there is no evidence to suggest that motor neurons prefer certain site on the developing myotube or that there is a predetermined site for the formation of the synapse, on the contrary, synapse formation can occur on most, if not all of the myotube surface (Lichtman et al in Zigmond et al 2000, pp. 547-8). Acetylcholine receptors (AChR) are found uniformly dispersed over the surface of the myotube until the nerve approaches the myotube. As the nerve approaches the myotube a protein known as agrin, which is synthesized in the motor neuron, is transported down the axon to the synaptic cleft where it is released from the nerve terminal, here it is deposited in the synaptic basal lamina. The major components of the basal lamina are laminins, which are made up of α, β and γ chains; it forms a continuous non-myelin layer over the nerve terminal and is a potent promoter of axon outgrowth. The basal lamina is present (at least components of the basal lamina are present) prior to the arrival of the nerve 2005-06-21T22:01:11-04:00 http://75.150.148.189/free-essay/The-Neuromuscular-Junction-as-a-Site-of-Disease-Process-27093.aspx The Biochemistry of Snake Venom Overview Snake venom is the poison fluid normally secreted by venomous snakes when biting. It is produced in the glands, and injected by the fangs. Snake venom is used to immobilize and/or kill prey, and used secondarily in defence. It is a clear, viscous fluid of amber or straw colour. There are two main types of venom produced by snakes, containing primarily either: *Neurotoxins - these attack the nervous system. *Hemotoxins - these attack the circulatory system. While most snakes' venom contains primarily either 2005-06-21T21:48:04-04:00 http://75.150.148.189/free-essay/The-Biochemistry-of-Snake-Venom-27088.aspx The Biochemistry of Human Energy systems With the aid of diagrams provide a summary of how the following energy systems work. Energy systems; introduction Energy systems are cellular levels processes used to produce Adenosine Triphosphate (ATP) figure 1. This is an adenosine molecule linked to three high-energy phosphates that acts as an energy store for the cell. The energy is released when ATPase, an enzyme, reacts with ATP to produce ADP and Pi, e.g. ATP ADP + Pi There are three energy systems that do this; •The Creatine Phosphate System •The Glycolytic or Lactic Acid system •The Oxidative system (The Krebs cycle, Citric Acid Cycle or Tricarboxylic Acid Cycle) The first too are ANAEROBIC, the third is AEROBIC. I.Creatine Phosphate (CrP) Summary: A cytoplasm based catabolic reaction in which Creatine Phosphate is degraded to Creatine to provide ATP; net profit of one ATP molecule; can proceed anaerobically. Net reaction: CrP + ADP+H+--->ATP + Creatine Detail: During high-intensity exercise energy for ATP resynthesis is provided primarily by another high-energy phosphate compound called creatine phosphate (CrP), see figure 2. Cellular concentrations of CrP are 4-5 times greater than that of ATP and are generally concentrated in areas of contractile protein; skeletal muscle has 95%. CrP is like a match; when the muscle receives a nerve impulse from the brain instructing it to contract, it instantly releases its energy, as if the match had been struck. This gives a natural "reservoir" of energy to enable resynthesis of ATP to occur rapidly, 7Toler (1997), 8Vandenberghe (1996) and 9Feldman (1999), but it can only sustain work at maximal levels for about 5 - 15 seconds dependant on activity level and the individual's personal physiological adaptations to exercise. The system has two steps. Firstly, bond between creatine and phosphate splits energy is liberated, as CrP has a higher potential energy than ATP, sufficient energy is released to resynthesise ADP to ATP. This reaction is catalysed by the enzyme creatine kinase. CrP Cr + Pi + energy The energy created in the split's useless to the cell directly; so in step two it's used to convert ADP and Phosphate to ATP and thus a source of useable energy to the cell. The process of ATP-CrP regeneration is the most rapid pathway for providing muscular energy. Energy ADP + Pi ------------------> ATP This is a 1:1 ratio in that one Creatine phosphate delivers one ATP molecule. This is not a very efficient system but it's very fast; 2005-06-21T21:45:29-04:00 http://75.150.148.189/free-essay/The-Biochemistry-of-Human-Energy-Systems-27086.aspx Bacteria Bacteria is a simple organism that consists of one cell. They are among the smallest living thing on earth. Most bacteria measures from about 0.3 to 2.0 microns in diameter, and can only be seen through a microscope. Scientist classify bacteria according to shape. Cocci are round and sometimes linked together. Bacilli look like rods, and Vibrios resembles bent rods. There are two types of spiral-shaped bacteria, spirochetes and spirilla. Bacteria exist almost anywhere you can think of. There are thousands of types of bacteria, most of which are completely harmless to the human body. Some species cause diseases while others are harmless. The Pros & Cons of Bacteria Certain kinds of bacteria live in the intestines of human beings and animals. These forms of bacteria are essential in the digestion process. They help the digestion process by eliminating and destroying harmful organisms. Intestinal bacteria also produces some vitamins needed by body. Bacteria cells resemble the cells of other living things in many ways, and so scientist study bacteria to learn more about complex organisms. For exmaple, the study of bacteria has helped researchers understand how certain characteristics are transferred through heredity. Most species of bacteria reproduce quickly. This enables many scientist to grow large quantities of research due to rapid reproduction of bacteria. Some kinds of bacteria cause diseases to human beings, animals and plants. The diseases include: cholera, gonnorhea, leporasy, gangrene, pneumonia, tuberculosis, tracheal bronchitis, syphilis, and typhoid fever. Bacteria enters the body through natural openings, such as the nose, mouth, and even breaks or cracks in the skin. In addition to transfer of bacteria through natural openings, bacteria is also transfered from one person to another by means of food, water, and air. Harmful bacteria prevents the body from functioning properly by destroying healthy cells. Certain bacteria produces posions which cause such diseases such as diperthia, tetanus, and scarlet fever. Some posions are produced by living bacteria while others are released only after bacterium dies. A form of food posioning called botulism is caused by posions from bacteria in improperly canned foods. Bacteria that may live harmlessly in the body can also cause infections. The infections are only minor compared to posion produceing bacteria. An example of this would include, if bacteria in the throat of a person with low immunity, reproduces faster than the persons body can dispose of them , the result is an infection 2005-06-17T09:02:11-04:00 http://75.150.148.189/free-essay/What-is-a-Bacteria-a-Research-Paper-26893.aspx Vitamin B6 and Vitamin B6 Deficiency A vitamin is any of various fat-soluble or water-soluble organic substances essential in small amounts for normal growth and activity of the body and obtained naturally from plant and animal foods. A mineral is naturally occurring inorganic solid substance having a definite 2005-06-16T09:41:15-04:00 http://75.150.148.189/free-essay/Vitamin-B6-and-Vitamin-B6-Deficiency-26882.aspx Freshwater Regions • Freshwater is defined as having a low salt concentration—usually less than 1%. Plants and animals in freshwater regions are adjusted to the low salt content and would not be able to survive in areas of high salt concentration (i.e, ocean). • There are different types of freshwater regions: ponds and lakes, streams and rivers, and wetlands. The following sections describe the characteristics of these three freshwater zones. • Ponds and Lakes - These regions range in size from just a few square meters to thousands of square kilometers. Scattered throughout the earth, several are remnants from the Pleistocene glaciations. Many ponds are seasonal; lasting just a couple of months (such as sessile pools) while lakes may exist for hundreds of years or more. Ponds and lakes may have limited species diversity since they are often isolated from one another and from other water sources like rivers and oceans. Lakes and ponds are divided into three different “zones” which are usually determined by depth and distance from the shoreline. • Streams and Rivers - These are bodies of flowing water moving in one direction. Streams and rivers can be found everywhere—they get their starts at headwaters, which may be springs, snowmelt, or even lakes, and then travel all the way to their mouths, usually another water channel or the ocean. The characteristics of a river or stream change during the journey from the source to the mouth. The temperature is cooler at the source than it is at the mouth. The water is also clearer, has higher oxygen levels, and freshwater fish such as trout and heterotrophs can be found there. Towards the middle part of the stream/river, the width increases, as does species diversity—numerous aquatic green plants and algae can be found. Toward the mouth of the river/stream, the water becomes murky from all the sediments that it has picked up upstream, decreasing the amount of light that can penetrate through the water. Since there is less light, there is less diversity of flora, and because of the lower oxygen levels, fish that require less oxygen, such as catfish and carp, can be found. • Wetlands - are areas of standing water that support aquatic plants. Marshes, swamps, and bogs are all considered wetlands. Plant species adapted to the very moist and humid conditions are called hydrophytes. These include pond lilies, cattails, sedges, tamarack, and black spruce. Marsh flora also include such species as cypress 2005-06-16T08:04:31-04:00 http://75.150.148.189/free-essay/Freshwater-vs-Marine-Water--26874.aspx Analysis of Charles Darwin's Origin of the Species Charles Darwin in his book, On the Origin of Species, presents us with a theory of natural selection. This theory is his attempt at an explanation on how the world and its species came to be the way that we know them now. Darwin writes on how through a process of millions of years, through the effects of man and the effects of nature, species have had a trial and error experiment ongoing. It is through these trials that the natural world has developed beneficial anomalies that at times seem too great to be the work of chance. Darwin writes on how a species will adapt to its surrounding given enough time. When an animal gains a genetic edge over its competitors, be they of the same species or of another genus altogether, the animal has increased its chance of either procreation or adaptation. When this animal has this beneficial variance, the advantage becomes his and because of this, the trait is then passed on to the animals offspring. The theory of natural selection is not limited to inheritable and beneficial variations of a species. It also relies a great deal on the population growth and death of a species. For a species to continue to exist it must make sure of a few things. It must first produce more offspring than survive. If this is not done then the species is obviously going to die off. It is also important for the species to propagate at such a rate as to allow for variance, for it is variance that will ultimately allow the animal to exist comfortably in his surroundings. In his studies, Darwin was led to understand that “…the species of the larger genera in each country would oftener present varieties, than the species of the smaller genera;” (p. 55). Thus the larger species would adapt while the smaller one would not. And to quote Darwin again, “…if any one species does not become modified and improved in a corresponding degree with its competitors, it will soon be exterminated.” (p. 102) Extinction, although not as pleasant a concept as the idea of adapting to ones surroundings, plays just as large a role in natural selection as anything else. As one adaptation of a species proves beneficial, and as that variation begins to propagate, the original, less advantageous variant will die off. 2005-05-27T07:31:07-04:00 http://75.150.148.189/free-essay/Analysis-of-Charles-Darwin-s-Origin-of-the-Species-26780.aspx The Plant Cell Cell Wall Size: Around 1µ Basic Function: * Hold the shape of the cell. * Strengthen the cell. Covering the cell membrane of the plant cell, there is the cell wall. The cell wall is composed of two layers of rigid, hard cellulose embedded in compounds like pectin and lignin. Pores in the cell wall allow molecules to pass through. The cell wall has two parts. The primary cell wall is formed during the growth of the cell. After the cell has stopped growing, a secondary cell wall forms. This secondary wall is made of lignin and cellulose, woven together tightly, to prevent further growth and to form and strong protective barrier. Cytoplasm Size: Unmeasurable Basic Function: * Helps dissolve waste products * Creates a "medium" for vesicles to travel through * Aids in cell metabolism * Serves as a home for the cytoskeleton. The cytoplasm is the jelly-like material that makes up much of the cell. It is 80% water and usually clear in color. It also contains many salts. The liquid portion is referred to as cytosol. In fact, "cytoplasm" means "cell substance." The cytoplasm is also the home of the cytoskeleton, a network of cytoplasmic filaments that are responsible for the movement of the cell. The cytoplasm is constantly moving and churning due to cytoplasmic streaming. Golgi Apparatus Size: Between 2 and 3µ Basic Function: * Serves as "processing center" for cell. * Packages and processes new proteins. * Prepares proteins for secretion or storage. The Golgi Apparatus is a series of stacked membranes in the cytoplasm that packages proteins for secretion or storage in vesicles. Inside the membranes are sacs of fluid or gel-like substances. The Golgi Apparatus takes proteins in transport sacs from the endoplasmic reticulum and sends it through a series of these membranes. The proteins are then "modified"' as they pass from membrane to membrane. After the vesicle of proteins has finished its trip through the Golgi Apparatus, it buds off the organelle in a Golgi sac, ready to be stored or transported to other parts of the body. Cell Membrane Size: 7 to 8 NM (nanometers) Basic Function: * Controls what enters and exits the cell. * Separates cell from outer environment. On the outside of all cells, there is a layer of protein and lipid (fat) called the cell membrane or the plasma membrane. This membrane is found in ALL cells. The 2005-05-26T10:04:08-04:00 http://75.150.148.189/free-essay/Notes-on-The-Plant-Cell--26747.aspx Greenhouse Effect The importance of the greenhouse effect was just conceived in the mid-twentieth century. "For billions of years, cosmic forces shaped Earth, and land and air coevolved at an almost inconceivably slow pace to create a climate in which human beings and other creatures could flourish." (Franscesca Lyman). Now, for the first time, humanity has the power to change the global climate. By releasing the huge amounts of carbon stored in fossil fuels over millions of years, we are distorting the natural carbon cycle. We are intensifying the natural greenhouse effect and turning it into a "planetary menace" when it actually makes human life possible. Thus, the German climatologist Wilfred Bach writes, "The carbon-dioxide problem becomes a central question for the co-existence of humans and the survival of mankind." If we do not deal with our problems now, such as global warming, the consequences will amplify and the consequences could mean our health, our life, our future. Could we, as humans, mend what we have destroyed? From the words of J.Stephen Bottum, "Constructive action begins with an understanding of what's causing the problem and what each of us can do about it." The greenhouse effect has been described by Vice President Al Gore as the potentially most dangerous environmental problem facing mankind, with consequences second only to nuclear war (The Greenhouse Trap). The greenhouse effect can be visualized as follows: Imagine the Earth has been encircled by a giant glass sphere. The heat penetrates through the glass. Some of the heat is absorbed by the Earth and some is radiated back towards space. The radiated heat reaches the glass sphere and is prevented from dispersing any further. Similarly, the Earth is surrounded by a blanket of gas which traps energy in the atmosphere. This results in the overall warming of the atmosphere. "For two hundred years we've been conquering nature. Now we're beating it up," says Tom McMillan. The greenhouse occurs naturally, but when humans put more greenhouse gases (carbon, methane, water vapor, and, nitrous oxide) and pollutants in the air the natural balance is off set. Since the beginning of industrialization, two hundred years ago, the gases have risen substantially, mainly from fossil fuels. This has produced a reduction in environmental quality and an increase in global warming. It is estimated that the Earth's average temperature has risen by five tenths to six tenths degrees Celsius since the 1880's 2005-05-26T09:32:04-04:00 http://75.150.148.189/free-essay/Greenhouse-Effect-Research-Paper-26728.aspx What is DNA? What is it used for? Forensic science uses techniques developed in DNA research to identify individuals who have committed crimes. DNA from semen, skin, or blood taken from the crime scene can be compared with the DNA of a suspect, and the results can hold important information that can put a criminal in prison, DNA doesn’t lie. DNA is not just used in forensic science but also in medicine. Through DNA technology, scientists can change microorganisms so that they become medicine. This technology is used to produce insulin, which is a drug used by diabetics, and interferon, which is used by some cancer patients. Using this powerful, weapon you can manipulate organisms to make products that benefit humans. Using Biotechnologies, you can alter food production, waste disposal, mining, and medicine. DNA stands for Deoxyribonucleic Acid. A molecule of DNA consists of two chains, that have chemical compounds called nucleotides. These chains are arranged like a ladder that has been, called a double helix. Each nucleotide consists of three units: a sugar molecule called Deoxyribose, a phosphate group, and one of four different nitrogen-containing compounds called bases. The four bases are adenine (A), guanine (G), thymine (T), and cytosine (C). The nucleotides in one DNA strand have a specific association with the corresponding nucleotides in the other DNA strand. Because of the chemical affinity of the bases, nucleotides containing adenine are always paired with nucleotides containing thymine, and nucleotides containing cytosine are always paired with nucleotides containing guanine. The complementary bases are joined to each other by weak chemical bonds called hydrogen bonds The DNA is located in the exact center of the nucleus. As you see, Guanine is always attracted by Cytosine, also Thymine is attracted by Adenine. Different variations of those four chemical compounds create different organisms of species that called a Repeat Sequence. For example, the Repeat Sequence, for the human species is TTAGGG. As for yeast its (TG)1-3TG2-3. So different species, have different formulas. If DNA makes one wrong, misplacement of any chemical, the organism can be corrupted, and well die soon. People who have corrupt or mixed DNA have Down syndrome or commonly called Mongolism disease. This disease causes people, to have learning disabilities and physical symptoms 2005-05-22T03:14:48-04:00 http://75.150.148.189/free-essay/What-is-DNA-What-is-it-used-for-26703.aspx Historical Development - Cell Theory 1. Robert Hooke - In 1662, he observed tiny compartments in the cork of a mature tree and gave them the Latin name cellulae (meaning small rooms). This was the origin of the biological term cell. 2. Anton Von Leeuwenhoek - By the late 1600s, he had observed diverse protistans, sperm, even a bacterium - an organism so small it would not be seen again for another two centuries. 3. R.J.H. Dutrochet - French botanist who prepared plant cells and studied them between 1824 and 1830. He discovered and named the phenomenon of osmosis, which is the passage of a liquid through a semi-permeable membrane. He was the first to carefully study respiration and light sensitivity in plants. 4. Robert Brown - In 1827, he noticed the constant presence of an opaque spot in egg cells, pollen cells, and then cells of the growing tissues of orchid plants and called this spot protozoa in 1834. 5. Dujardin - He discovered one -celled animals called rhizopoda, now called protozoa in 1834. 6. Matthias Schlieden - In 1838, he suggested that the nucleus and cell development are closely related. He decided that each plant cell leads a double life - one independent, involving its development, the other as an integral part of the plant. 7. Theodor Schwann - In 1839, after years of studying the structure and growth of animal tissues, he concluded that animals, as well as plants, consist of cells and cell products, and even though the cells are part of a whole organism, they have an individual life of their own. 8. Rudolf Virchow - In 1849, he completed his studies of cell growth and reproduction of their division into two cells. He concluded that every cell comes from an already existing cell. 9. Walther Flemming - In the early 1880s, while using dyes to study the structure of cells, he found a structure, which strongly absorbed dye, and named it chromatin. He observed that the chromatin separated into stringy objects during cell division, which became known as chromosomes. Flemming named the division of somatic cells mitosis, from a Greek word for thread. He also observed that the chromosomes formed two star shaped structures on either side of the dividing cell, which he named asters. 10. C. Golgi - In 1898, he described the existence of a network of thread like structures and small sacs (vesicles) in the cytoplasm of nerve cells. This complex organelle composed of flattened sacs and vesicles is now known 2005-05-16T06:22:11-04:00 http://75.150.148.189/free-essay/Historical-Development-of-Cell-Theory-26636.aspx The Fire Ant Research Paper The "Fire Ant" is one of the most feared migratory arthropods in North America. The first non-native species was introduced into the Port of Mobile, Alabama, starting in 1919, through soil ballast, from South American ships, being dumped ashore. The black fire ant (Solenopsis richteri Forel) arrived sometime in 1919, and the red fire ant (Solenopsis invicta Buren) sometime in the late 1930's; both much more aggressive and harsh than their two sister species of fire ants, the Tropical fire ant (Solenopsis xyloni McCook) and the Southern fire ant (Solenopsis geminata Fabricius), which are considered native to North America. The presence of imported fire ants within United States boarders was first reported in 1929. Currently, the IFA (imported fire ant) is found in eleven states (over 300 million acres) , with sporadic, isolated showings as far west as California and as far north as Kansas and Maryland. The surge in fire ant migration came right after world war two, with the housing boom. The migration of fire ants was mostly associated with the mass movement of grass sod and decorative plants for landscaping purposes. However, "In 1958, the Federal Fire Ant Quarantine was implemented [to] try to limit the spread of fire ants from the quarantined areas. Hay, sod, plants and used soil moving equipment must me inspected and/or treated before being moved out of the quarantine area." The IFA migration methods include "...seasonal relocations, migration in nursery stock, natural flights, and after floods rafting on water. Ants can be blown by the wind 12 miles during mating flights. They can "hitchhike" on birds [or other animals] or mass together to form a floating ball to ride out a flood." It is estimated that a fire ant colony can expand 20-30 miles per year based on mating flights alone. The IFA migration fear is due to damage to people, but also damage to crops and property. Currently, the IFA is known "...as damaging 57 different species of cultivated plants" including wheat, cotton, corn, sorghum seed, soybean, blueberry, peanut, sunflower, watermelon, cantaloupe, cucumber, pecan, eggplant, okra, strawberry, and potato in addition to property, fire ants have been associated with may outdoor electrical equipment, due to their strong attraction to electrical and magnetic fields and impulses. The effected items where fire ants 2005-05-16T05:02:33-04:00 http://75.150.148.189/free-essay/Profile-of-The-Fire-Ant--26624.aspx Dinosaurs and Birds Are birds really dinosaurs or are they simply related? That is a question that has gained new life in recent years due to the overwhelming facts the are pouring in from newly found fossils and studies from fossils that have been found in the past. Two groups have formed in the study of this question: those who believe birds are a direct result of dinosaurs and those who feel dinosaurs and birds must have had a common ancestor. Determining which view is correct is a matter of opinion based on fact. The main problem involves the use of cladistics or phylogenetic systematics to group organisms according to characteristics they share. When one looks at dinosaur fossils, he or she may feel that certain characteristics are used for something entirely different than someone else who has looked at the same fossil. One cannot talk about dinosaur and bird lineage without mentioning Archaeopteryx. Most paleontologists agree that Archaeopteryx was the first bird. Archaeopteryx thus represents what paleontologists would call a "transitional form" between two major groups of animals, the reptiles (dinosaurs) and birds. The main difference between the theropods and Archaeopteryx were the long arms of the Archaeopteryx, adapted as wings, the feathers, and the presence of a wishbone that the theropods did not have. All of these features tie it to birds and its other characteristics tie it to theropods. One might say it was the "missing link" between the two. Opponents of this idea say that the similarities between Archaeopteryx and theropods were due to convergence, with the birdlike dinosaurs appearing in the Cretaceous some 75 million years after Archaeopteryx. Also, support is gaining that Archaeopteryx was not in fact the first bird, but instead a descendent of an earlier bird ancestor that had developed along a different pathway and actually represents an evolutionary dead end. Two opponents of the "birds are dinosaurs theory" are Alan Feduccia of the University of North Carolina and Larry Martin of the University of Kansas. They believe that birds evolved from some unknown reptile from a time before dinosaurs came to be. One point they make is that flight must have begun from tree climbing or an arboreal ancestor but that all the proposed dinosaurian ancestors were ground dwellers or cursorial On the other side, supporters for the "birds are dinosaurs theory" feel 2005-05-16T04:56:09-04:00 http://75.150.148.189/free-essay/Evolution-Are-Birds-Descendants-of-Dinosaurs-26623.aspx Hydroponics: Advantages of Producing Crops Through Use of Hydroponics HYDROPONICS derives its name from the Greek HYDRO-PONOS meaning water/labor. Literally, "Hydroponics" means "Water Work." There is no soil in a hydroponic garden. No organic matter is present so nourishment (Nutrient) is not available to the plants in the same was as it is in a soil garden. Instead, nutrients are added to the water. So, as plants are watered, they are also fed. There are many ways to feed and water plants. The method 2005-05-16T04:15:10-04:00 http://75.150.148.189/free-essay/Advantages-of-Hydroponics-26619.aspx Mechanisms of Genetic Exchange: Transformation and Conjugation Introduction Genetic exchange had been known to play a role in the evolution and survival of microorganisms. Genes of one bacterium can be exchanged to another through several different ways: conjugation, transformation and transduction. However, the focus of this paper is to further examine the characteristics of conjugation and transformation mechanisms. Transformation was first discovered in 1928 by Frederick Griffith while he was studying pneumococcal infection in mice.1 In 1944, Avery, McCleod and McCarthy discovered that the transforming substance is DNA.1,2 Transformation occurs when a naked, double-stranded DNA was taken from outside into the cell, may be followed by the integration of the DNA into the host’s chromosome, and also replication, transcription and expression of the information encoded in the DNA.1,2,3 However, the recipient cell must be competent- do not secrete DNAase- upon the intake of the DNA fragment (from the donor) in order for the DNA fragments to be recombined into the recipient cell’s chromosome.2 In other words, transformation can be made to be more efficient if the DNAase do not exist since the enzyme acts as a digestor of foreign DNA.4 An advantage of transformation is the fact that the DNA can be subjected to mutagenesis and other treatments or manipulations, enabling the analysis of the bacterial genome. A disadvantage to the transformation method is the fact that this method can only produce small percentage of transformation in most bacteria.3 Due to the much smaller sizes of the transforming fragments and their competition for uptake with many other DNA fragments, the probability that a recipient cell incorporated the desired DNA fragment is very slim.4 Conjugation is another method that is very adaptable and efficient for intra- or inter- species genetic transfer.3 First discovered in 1946 by Lederberg and Tatum in a strain of E.coli called K-12, conjugation requires physical contact between two genetically different cells via a conjugation tube called the F-pilus, which transfers the F factor.1,2,4 The F factor is acquired by conjugation from an F+ to an F-. The F factor has a size of approximately 1/50 the size of the E.coli chromosome and it has no connection to the bacterial chromosome, thus the F factor and the chromosome replicated independently of each other. Eventhough the F factor is not involved in the normal function of the cell and it is dispensable, it is the determinant in the “organism’s 2005-05-14T00:53:17-04:00 http://75.150.148.189/free-essay/Genetic-Exchange-Transformation-and-Conjugation-26593.aspx Human Cloning The possibility of human cloning was raised when Scottish scientists, led by Dr. Ian Wilmut at the Roslin Institute, created the much-celebrated sheep "Dolly". Being the first mammal ever cloned this aroused worldwide interest and concern because of its scientific and ethical implications. The feat, cited by “Science Magazine” as the “breakthrough of 1997”, also generated uncertainty over the meaning of "cloning" -- an umbrella term traditionally used by scientists to describe different processes for duplicating biological material. Since this creation, mice, goats, cows and pigs have been successfully cloned around the world. This has made human cloning a real possibility. Cloning is the production of one or more individual plants or animals that are genetically identical to another plant or animal. It is different from natural fertilisation which is "sexual" reproduction that occurs when a sperm fertilises an egg. In normal fertilisation the developing embryo (and person) has the genetic makeup or DNA of both parents 23 chromosomes from the female and 23 from the male. The embryo is the unique human organism with a novel genetic makeup having the full potential to develop to adulthood. Current definitions define "embryo" as follows: “the term `human embryo or embryos’ includes any organism that is derived by fertilisation, parthenogenesis, cloning, or any other means from one or more human gametes or human diploid cells.” Figure 1: Comparing cloned embryo’s with fertilised embryo’s Source: Available from URL: http://www.house.gov/weldon/issues/clone_basics.htm#cloning (Accessed Sunday 15th August 2004) When the media report on cloning in the news, they are usually talking about only one type called reproductive cloning. There are different types of cloning however, and cloning technologies can be used for other purposes besides producing the genetic twin of another organism. A basic understanding of the different types of cloning is the key to taking an informed stance on current public policy issues and making the best possible personal decisions. The three main types of cloning are: 1. Embryo cloning 2. Reproductive cloning 3. Therapeutic cloning Embryo cloning Embryo cloning might be more accurately called "artificial twinning", because it simulates the mechanism by which twins naturally develop. It involves removing one or more cells from an embryo and encouraging the cell to develop into a separate embryo with the same DNA as the original. It has been successfully carried out for years on many species of animals. Some very limited 2005-05-10T04:36:34-04:00 http://75.150.148.189/free-essay/Human-Cloning-Controversial-Research-Essay-26588.aspx What is Heredity? Research Essay on Heredity heredity {hur-ed'-i-tee} Heredity is the transmission from one generation to the next of factors that determine the traits of offspring. Although successful breeding of plants and animals was practiced by humans long before modern civilizations were established, there is no evidence that these early people understood the nature of hereditary factors or how they are transmitted through reproduction. EARLY HISTORY One of the early Greek philosophers, Pythagoras (582-509 BC), postulated that all traits of an offspring are derived solely from its father's semen. Aristotle thought that females also produce semen and that the embryo is formed by a fusion in the uterus of both types of semen. He further postulated that both male and female semen are produced by the body's blood. Leeuwenhoek Until the 17th century, European medical schools taught that hereditary factors in the semen were derived from vapors emanating from each body organ. However, Anton van LEEUWENHOEK observed human semen through his microscope and reported finding "animalcules." It became generally accepted that sperm were the actual carriers of hereditary factors from males to their offspring. Other biologists studied the ovaries of animals, noted the presence of swollen bodies--which they correctly assumed contained eggs--and hypothesized that these eggs were also units of transmission of hereditary factors. Epigenesis Some biologists of the 17th and 18th centuries believed that they saw miniature individuals in the sperm or eggs of various organisms, an observation that led to the doctrine of preformation. According to this theory all parts of the adult are already formed at the beginning of embryonic life, and as a result, embryonic development consists solely of growth. Toward the end of the 18th century, Caspar Friedrich WOLFF conducted extensive investigations on developing chicken embryos. He demonstrated that the adult parts of the animal are not present at the beginning of embryonic life but are formed during the developmental period. His doctrine of DEVELOPMENT, known as epigenesis, has been substantiated by countless observations and experiments. It is important to note that the biologists who disproved preformation and advanced the idea of epigenesis 200 years ago still held beliefs similar to those of the ancient Greeks on the origin of the hereditary material. The 18th-century scientists thought that the individual body organs produced tiny particles that had the potential of forming in offspring the same structures as that of the parent. These biologists postulated that the particles from the various organs would be transferred to 2005-04-13T03:07:29-04:00 http://75.150.148.189/free-essay/Research-Paper-on-Heredity-and-Pioneers-26493.aspx Reproduction: What is love? Is love real? Or is it just reproductory? REPRODUCTION: A-Courting to Nature! For some time she had watched his movements, appearing coyly in his haunts. And now, had it paid off? Doubtless, he was in love. His muscles were taut; he swooped through the air more like an eagle than a Greylag gander. The only problem was, it was not for her that he then landed in a flurry of quacks and wingbeats, or for her that he dashed off surprise attacks on his fellows. It was, rather, for another - for her preening rival across the Bavarian lake. Poor goose. Will she mate with the gander of her dreams? Or will she trail him for years, laying infertile egg clutches as proof of her faithfulness? Either outcome is possible in an animal world marked daily by scenes of courtship, spurning and love triumphant. And take note: these are not the imaginings of some Disney screen-16 writer. Decades ago Konrad Lorenz, a famed Austrian naturalist, made detailed studies of Greylags and afterwards showed no hesitation in using words like love, grief and even embarrassment to describe the behavior of these large, social birds. At the same time he did not forget that all romance - animal and human - is tied intimately to natural selection. Natural selection brought on the evolution of males and females during prehistoric epochs when environmental change was making life difficult for single-sex species such as bacteria and algae. Generally, these reproduced by splitting into identical copies of themselves. New generations were thus no better than old ones at surviving in an altered world. With the emergence of the sexes, however, youngsters acquired the qualities of two parents. This meant that they were different from both - different and perhaps better at coping with tough problems of survival. At the same time, nature had to furnish a new set of instincts which would make "parents" out of such unreflective entities as mollusks and jellyfish.. The peacock's splendid feathers, the firefly's flash, the humpback whale's resounding bellow - all are means these animals have evolved to obey nature's command: "Find a mate. Transmit your characteristics through time!" But while most males would accept indiscriminate mating, females generally have more on their minds. In most species, after all, they take on reproduction's hardest chores such as carrying young, incubating eggs and tending newborns. Often they can produce only 2005-04-13T03:04:19-04:00 http://75.150.148.189/free-essay/Reproduction-What-is-Love-Is-Love-Real-26492.aspx Please give a grade to this essay after reading/downloading this essay. Back to southern China 2000-3000 yrs ago, virologists generally believed that in domestication of ducks there, flu jumped species. A new virus is a cross-species transmission in which the virus has mutated from its animal vector so that it can infect human beings. Generally speaking, the most manifest examples are influenza and HIV (Human Immunodeficiency Virus) and the latest and the acutest case—SARS (Serve Acute Respiratory Syndrome). Back to the past, there were several calamitous cases which were all due to mutated viruses and caused a lot of death. From the history, around the whole planet, the “Russian flu” of 1889-1890 is thought to have slew 250,000 people in the whole Europe. In a more severe case, the “Spanish flu” of 1918, estimated to cause 40 million deaths in a year. In a later time, the virus dispersed to Philadelphia in USA and the deadly bug contributed a further death of 7,500 there. With the more advanced medical treatments and better sanitary condition, the aftermath of a new virus was greatly mastered and reduced, though virus does continue to mutate into a new species from original avian vectors. For instance, Hong Kong’s “bird flu” broke out in 1997. This virus was part human and part avian and its damage has much less obvious, compare to the first two cases. People over the world have a confidence that influenza virus will not be a great problem to our health anymore. However, most recently, a new plague break out in Hong Kong. Because of our confidence, the experts and scholars seem to underestimate the situation of it. However, the fear behind becomes more apparent. Will it be a minor analogy of “Russian flu” or “Spanish flu”? The SARS outbreak underlines the importance for early warning, given the threats that such rapidly transmitted new diseases pose. The disease could be spread to more countries if information is not made available. The SARS outbreak is an example—or a sign, a sign that shows any new break-out disease can pose certain degree of threat to us since we have no idea and information on what it is. “It is not as if viruses have suddenly got more muscular in the past two years” (TIME, Vol. 141 No. 13 P.58). The new 2005-04-06T09:20:40-04:00 http://75.150.148.189/free-essay/Birth-of-a-Deadly-Bug-26470.aspx INTRODUCTION History of ATM Asynchronous Transfer Mode or ATM came about through the evolution of the Integrated Services Digital Network (ISDN) in the 1980's and the demand for high-speed packet communications. This extended further into the higher speed solution of Broadband ISDN with the intention to provide integrated broadband services such as high-speed telephone, data and video communications. In 1988, the International Telecommunications Union (ITU) defined ATM as the vehicle for B-ISDN with a view to it becoming the universal network transport. It is the ability to serve different service types, together with fast transmission rates and low overheads, which is leading to the widespread use of B-ISDN today. More information may be obtained from [Ref. 6] Efficiency Issues of a Transmission System In the transfer of data, whether it be voice, video or computer data it is common to use some form of compression technique in order to use the transmission medium efficiently. These data compression techniques commonly include some form of Run Length Encoding (RLE) to remove redundancy within a signal and thus reduce the bandwidth consumed by the transmission. Although, data compression is performed at a much higher level, ATM achieves its efficiency by making use of small, compact packets with a small header field, maximising the user information to system overhead ratio leading to higher data rates than other transmission mechanisms. Image and Video Compression Again in the late eighties, the MPEG standard for video compression was born and defined as a compression standard mainly for CD-ROM applications. This standard was closely followed by the MPEG-2 standard widely used today in the compression of pre-recorded video. Unlike M-JPEG compression, MPEG-2 works by predicting the movement of objects within a picture, producing a series of related frames each of which depends on a single start image. The relationships between frames can become very complex unlike those in M-JPEG compression, which may function independently or in a video stream. As MPEG compression is beyond the scope of this project more information on the mechanisms involved may be found in [Ref. 4, 5, 6]. Applications for ATM ATM has enough flexibility to provide transport for a wide range of services including audio, video and raw data. Not only may it accommodate any one of these, but also it may successfully accommodate a mixture of data types. Each type however has its own optimum transmission characteristics. Transfers such 2005-03-29T02:03:12-04:00 http://75.150.148.189/free-essay/History-of-Asynchronous-Transfer-Mode-ATM-26457.aspx Environmental Effects of Global Warming In order to talk about global warming, we must first learn what causes the greenhouse effect. A lot of the rays from the sun are absorbed by water vapor that is naturally in our atmosphere. Water vapor accounts for "80 percent of natural greenhouse warming. The remaining 20 percent is due to other gasses that are present in very small amounts1". Carbon dioxide is also a big absorber of the sun's heat rays. Global warming will not just make sea levels rise, it will also affect sea life. Corals "are intolerant of temperatures just a few degrees warmer than usual7". Small increases in the temperature can kill corals. There have been problems with corals dying in the past few years because of increased water temperatures. Other marine life may migrate northward or southward because the waters are warmer. The warm water would make them think that they were in their natural habitat, when they were actually migrating toward the poles. Food would be scarce in their new habitat. Patterns of the circulation of sea water are disturbed by global warming. Cold water moves along the sea floor towards the equator and warm water around the equator moves toward the poles across the surface of the ocean. It is known as thermohaline circulation. It is a very important process concerning ocean life. This circulation process brings oxygenated water to the sea floor. If this did not happen, "water along the sea floor would become depleted of the oxygen organisms need to survive8". Fish, such as salmon, are also sensitive to the temperature of the water. During the summer when the water is warm, salmon have a higher metabolic rate. During the winter months, their metabolism slows down, which is good because less food is available. With global warming and increased water temperatures, salmon would have a higher metabolic rate, even if it were during the winter. Less food would be available for them and many salmon would die. Another impact of global warming will be that some diseases are likely to be spread more easily. Mosquitoes are a major carrier of tropical diseases. Malaria outbreaks are usually confined to "where the minimum winter temperature reaches no lower than 16 [degrees Celsius]," according to the World 2005-03-29T01:47:43-04:00 http://75.150.148.189/free-essay/Environmental-Effects-of-Global-Warming-26450.aspx About 1 out of 201 Caucasian people carries at least one of the fatal defective genes that cause cystic fibrosis, CF, or mucoviscidosis (in Europe) although carriers don't show any signs of the disease. Therefore, 10 million2 people carry the defective gene and aren't aware of it. Consequently, it makes it one of the most common genetic defect in the United States. CF is a autosomal recessive gene. That means that it may, but doesn't always skip generations. In order to get this disease, both parents must be carriers. If one parent has CF and the other one is not a carrier than there is a 100% chance that their child will be a carrier. If one parent has CF and the other is a carrier than the child has a 50% chance of having CF and a 50% chance of just being a carrier. If both parents are carriers than their child will have a 25% of having CF, a 50% chance of being a carrier and a 25% chance of not being affected. CF is common in both males and females, there is not a specific sex that it is more common in. How does a person know if they have CF? There are many symptoms to this deadly disease including: salty tasting skin, constant coughing, large amounts of mucus, trouble gaining weight, frequent greasy, foul smelling bowel, growths in the nose (nasal polyps) and clubbed or enlarged fingertips and toe tips is another symptom. Now there are many tests that can be done to find put if a person has CF. One way which CF can be detected is to observe the symptoms. A person doesn't need to have all the symptoms in order to have cystic fibrosis, but they usually show most of them. Another way are different genetic testing. Doctors can now do genetic testing for CF, but about 10 years ago they couldn't. In 1989, the location where the of the defective gene on chromosome number 7 is was discovered by Francis S. Collins from University of Michigan. Tests can now be taken to see if an unborn child is infected with CF such tests are amniocentesis, chronic villus biopsy3 and a removal of cells from the embryo during invitro. Many years ago, New York4 had a heat wave, and the hospitals became overwhelmed with dehydrated CF children. These children became dehydrated much quicker than children 2005-03-24T04:02:31-04:00 http://75.150.148.189/free-essay/Cystic-Fibrosis--26397.aspx Nerve Agents: Tabun, Sarin, and Soman IV Now imagine that you are on a beach code-named OMAHA during World War II. As you travel inland from the beach, suddenly you see your commanding officer on the ground; he is dead but not from a bullet wound. After you take a few steps away from him you start to shake, very hard, then all of a sudden everything goes BLACK, into oblivion. You have just been a victim of one of the most deadly gases ever developed before or after World War II. Even though nerve agents were never used in World War II, if they had the outcome might have been very different. The creation and little known facts about nerve agents, like Tabun, Sarin, and Soman are very interesting. The development of, and original usage of the first nerve agent, proves very enlightening. This is an in depth look at some of the deadliest nerve agents ever created. Dr. Gehard Schrader, who was a pesticide specialist, in Leverkusen, Germany at the I.G. Farbindurstrie laboratory created the first nerve agent(“Chemistry of GA”). Schrader first created what he called Tabun on December 23, 1936(“Short History”). About one year later Schrader and his assistant started showing symptoms of meiosis, the contraction of the pupils of the eye, and they also had some shortness of breath. It was later said Schrader was lucky to escape with his life. On the more scientific side, the chemical structure contains five different atoms and they are seven carbons, eleven hydrogen, two nitrogen, two oxygen and phosphorus. What is unique is phosphorus is the center of the molecular structure(“Chemistry of GA”). The American classification of Tabun is GA; all nerve agents of this origin are called the G-series nerve agents. Schrader sent a sample of GA to the chemical warfare department in 1937,as for told in a Nazi decree in 1935, after his close call (“Short History”). Dr. Gerhard Schrader also created the second nerve agent in1938 at an undisclosed location in Germany(“Short History”). I was not able to find any information on its effects suffered by a person that has been exposed to Sarin. Sarin like Tabun has five atoms four carbon, ten hydrogen, fluorine, two oxygen and phosphorus, the chemical structure has phosphorus as the center(“Short History”). As there is no known use of Sarin in wartime, it is speculated that Sarin was used in a town during 2005-03-19T22:34:07-04:00 http://75.150.148.189/free-essay/Nerve-Agents-Tabun,-Sarin,-and-Soman-IV-26378.aspx Tomas Izquierdo has not slept since 1945. Due to an attack of encephalitis, an inner brain inflammation, his ability to fall asleep was lost at the age of 13. Although he rests with his eyes closed, his brain patterns are those of someone who is fully awake and aware. He has memory problems and very sensitive eyes, but is otherwise completely normal. To relax, he usually uses transcendental meditation from about three or four AM until the morning (Coleman 94). Tomas Izquierdo is what one might call someone without circadian rhythms. Circadian rhythms are the daily sleep patterns of humans. Circadian rhythms tell people when they are most alert, when they feel tired, and when they should wake up. These circadian rhythms, while difficult to research, are important to many industries, as well as a multitude of sleep disorder patients. For several years, scientists and doctors have been seeking a greater understanding of these patterns through constant, difficult, and fast paced research. The applications of such knowledge would be quite beneficial in shift based industries as well as some special circumstances. As of yet, doctors have been able to determine a few important correlations between internal time cues and sleep, activities or events that give cues to the brain about what time it is or should be. However, the research is very difficult. Researching sleep is difficult for a variety of reasons. The first reason for difficulty is the nature of experimentation. To truly isolate the sleep patterns, all time-giving cues, or zietgebers, have to be eliminated. Light, electromagnetic waves, the schedules of researchers, and even the growth of a facial hair on outsiders may lead the subject to guess the time of day. The body can detect even the faintest cues of time, so it is incredibly important that the subject be completely shut off from time giving cues. If the subject of the research knows the time of day, he or she may adjust accordingly, skewing results and making it all but impossible to collect the data needed. Another reason for the difficulty of sleep research is the pace of discovery. The field moves too fast for its own good. As a result, no comprehensive beginner’s text is available in the field of circadian rhythms. By the time a book would go to print, too much important experimental evidence would have been released for it to be considered up to date. 2005-02-23T09:46:10-05:00 http://75.150.148.189/free-essay/Circadian-Rhythm-and-Sleep--26334.aspx Sun Effects The Skin Since 1980s, that we have started hearing how bad the sunlight can be for the skin and it is surprising to see millions of people still lying on the beach every summer, or working out in the sun from days to days. In United States, more than 600,000 cases of skin cancer were been reported in 1999, most of them caused by too much exposure to ultraviolet rays from the sun. Can you believe that? Around 30,000 of these cases will be the most dangerous kind of cancer, called melanoma, a kind of skin cancer which is directly related to exposure to the sun, and approximately 6,500 people will die from it. These kinds of statistics should really make us a big impact of the dangers of the sunlight. Also, about one out of every six people will develop some form of skin cancer and more than 90 percent of those cases will be directly related to exposure to the sun. Part 2 Who is most likely to suffer from the most serious form of skin cancer? There are three major factors that raise a person's risk of getting melanoma. Firstly, there is a hereditary factor. Hereditary factors are factors we are born with- our general genetic makeup, such as our skin and hair color. In general, light-skinned, light-eyed people of northern European background are most likely to suffer from skin cancer. These people often have red or blond hair. In contrast, dark-haired Caucasians, Asians, and Hispanics suffer less from this disease, and dark-skinned people are 50 times less likely than light-skinned people to get skin cancer. Secondly, it is the environmental factor. Where we live seems to influence our chances of contracting the disease. Geography has the direct relationship with skin cancer. The further away, north or south, of the equator you are, the less likely you are to get skin cancer because the sunlight are not directly overhead, but instead hit the Earth at a softer angle. For example, someone who lives in southern Florida, where is fairly near the equator, is more likely to contract this disease than someone who lives in Alaska, where the sunlight are never directly overhead. This means that the rays take longer to reach the Earth, so the ozone layer of the Earth's atmosphere is able to stop more of the sun's dangerous ultraviolet light. One interesting topic I read recently that a 2005-02-20T05:26:34-05:00 http://75.150.148.189/free-essay/The-Effects-of-Sun-on-Skin-such-as-Cancer,-etc_-26269.aspx About Cell Organelles The studies of Robert Hooke 1665 into a plant material would allow the determination of a pore like regular structure surrounded by a wall of which he called ‘cells’ this in itself unbeknownst to him, was the discovery of the fundamental unit of all living things. In 1838 a botanist called Schleiden derived the theory ‘The basic unit of structure and function of all living organisms is the cell.’ Over 150 years later this can be regarded as one of the most familiar and important facts within the biological fields. Drawing of cork cells published by Robert Hooke 1665 The Cell itself and use of Cytology: The cell can be thought of as a bag in which the chemistry of life is allowed to occur, partially separated from the environment outside the cell, it exists within all living organisms as its basic structure. The study of cells is made possible through the use of ‘cytology’ the preparation of materials for examination through microscopes as an average animal cell exists on a scale of 10 microns roughly one hundredths of a millimetres. Originally light microscopy was used in this field but with the advancement of knowledge scientists were restricted to 200nm magnification, or 2 tenths of a micron. Realising the existence of cell organelles within the cell structure, allowing the function of the cell itself to occur; It was necessary to increase magnification by utilising an alternate source radiation (alternate to light).The result was the electron microscope, whereby the short wavelength and negative charge of electrons when supplied with energy allowed for greater focusing with electromagnetism. This method bends the path of the beam in the manner of a lens to light. Cell Organelles and the variation between Plant and Animal Cells: We have already determined the cell to be the foundation to all organisms, however the term cell is associative and categorises a wide variation. Every animal cell has a specified function whether it be the production of hair, mucus, or the process of other chemicals ( multiple reactions occur within a cell for other purposes i.e. creation of ATP, protein manufacture etc.) So from this we must examine the cell in more detail and determine what it is within the cell that creates it specialised function and separates it as an individual type. Plant cells vary from animal through the existence of certain organelles. Organelles are the 2005-02-03T00:52:41-05:00 http://75.150.148.189/free-essay/Cell-Organelle-Overview--26252.aspx Vegetated sand ridges called dunes, built up by dry beach sand blown inland and trapped by plants and other obstructions, back most beaches. As sand accumulates, the dunes become higher and wider. Plants play a vital role in this process, acting as a windbreak and trapping the deposited sand particles. A characteristic of these plants is their ability to grow up through the sand and continually produce new stems and roots as more sand is trapped and the dune grows. Stable sand dunes play an important part in protecting the coastline. They act as a buffer against wave damage during storms, protecting the land behind from salt-water intrusion. This sand barrier allows the development of more complex plant communities in areas protected from salt-water inundation, sea spray and strong winds. The dunes also act as a reservoir of sand, to replenish and maintain the beach at times of erosion. Frontal sand dunes are vulnerable. The vegetation can be destroyed by natural causes such as storms, cyclones, droughts or fire, or by human interference such as clearing, grazing, vehicles or excessive foot traffic. If the vegetation cover is damaged strong winds may cause 'blowouts' or gaps in the dune ridge. Unless repaired, these increase in size, the whole dune system sometimes-migrating inland covering everything in its path. Meanwhile, with a diminished reservoir of sand, erosion of the beach may lead to coastal recession. To avoid this, protecting the vegetation is vital. The beach, between high and low tides, is hard-wearing but the sensitive dunes, which we cross to reach it, must be protected also. For this reason damaged and sensitive dunes might need to be fenced and access tracks for vehicles and people provided. Processes such as waves, near shore currents and tides continually modify shorelines. The ability of beaches to maintain themselves is achieved through these natural forces. The natural process of beach renourishment, sometimes called "dynamic equilibrium", is how the beach responds to weather. When waves are high during storms or when hurricanes hit the shore, sand is carried from the beach and deposited on the ocean floor. This makes the ocean bottom flatter and makes waves break further from shore and smaller. During subtle weather or erosion, smaller waves slowly shift the sand back to the shore and replenish the beach. When people build homes or resorts on beaches, the buildings interrupt this natural process because the sand that is usually taken 2005-02-02T09:34:18-05:00 http://75.150.148.189/free-essay/Beach-Dune-Erosion--26239.aspx An Overview of Bacterial Life and Its Place in the Ecosystem Bacteria are often maligned as the causes of human and animal disease (like this one, Leptospira, which causes serious disease in livestock). However, certain bacteria, the actinomycetes, produce antibiotics such as streptomycin and nocardicin; others live symbiotically in the guts of animals (including humans) or elsewhere in their bodies, or on the roots of certain plants, converting nitrogen into a usable form. Bacteria put the tang in yogurt and the sour in sourdough bread; bacteria help to break down dead organic matter; bacteria make up the base of the food web in many environments. Bacteria are of such immense importance because of their extreme flexibility, capacity for rapid growth and reproduction, and great age - the oldest fossils known, nearly 3.5 billion years old, are fossils of bacteria-like organisms. Bacteria grow in a wide variety of habitats and conditions. When most people think of bacteria, they think of disease-causing organisms, like the Streptococcus bacteria growing in culture in this picture, which were isolated from a man with strep throat. While pathogenic bacteria are notorious for such diseases as cholera, tuberculosis, and gonorrhea, such disease-causing species are a comparatively tiny fraction of the bacteria as a whole. Bacteria are so widespread that it is possible only to make the most general statements about their life history and ecology. They may be found on the tops of mountains, the bottom of the deepest oceans, in the guts of animals, and even in the frozen rocks and ice of Antarctica. One feature that has enabled them to spread so far, and last so long is their ability to go dormant for an extended period. Bacteria have a wide range of envronmental and nutritive requirements. Most bacteria may be placed into one of three groups based on their response to gaseous oxygen. Aerobic bacteria thrive in the presence of oxygen and require it for their continued growth and existence. Other bacteria are anaerobic, and cannot tolerate gaseous oxygen, such as those bacteria which live in deep underwater sediments, or those which cause bacterial food poisoning. The third group are the facultative anaerobes, which prefer growing in the presence of oxygen, but can continue to grow without it. Bacteria may also be classified both by the mode by which they obtain their energy. Classified by the source of their energy, bacteria fall into two categories: 2005-01-20T08:12:38-05:00 http://75.150.148.189/free-essay/The-Dirt-on-Bacteria--26171.aspx Charles Darwin proposed the theory of evolution to explain the origin, diversity and complexity of life. I will will disprove evolution by showing that natural selection only explains small evolutionary changes, collectively known as microevolution. Natural selection cannot drive large evolutionary changes, macroevolution. I will also show that the primordial soup, in which life supposedly evolved, did not exist. Neo-Darwinism incorporates the discoveries of modern science into Darwin's original theory while leaving the basic beliefs intact. Darwin proposed that individuals with favorable traits are more likely to survive and reproduce. Darwin called this process natural selection. Darwin did not understand how or why variation existed. Today scientists realize that variation arises through random changes (called mutations) to existing genes. Genes are the chemicals that determine the traits and characteristics of animals and plants. Every trait has one or more gene associated with it. Thus, natural selection provides the animals and plants with the best genes. Supporters of neo-Darwinism believe that natural selection operating upon random variation gave rise rise to all animals and plants. While the source of variation is random, the direction of evolution is not. In effect, natural selection removes chance, and it makes the theory of evolution plausible. If neo-Darwinism is correct then numerous small successive changes guided by natural selection gave rise to all animals and plants. I will prove that natural selection is not a creative process. Its primary function is to preserve the status quo. Thus, new structures and organs must arise through chance. Natural selection can only preserve and optimize these new structures and organs after they evolve through chance. In other words, natural selection does not drive evolution, and the hypothesis on which neo-Darwinism is based is flawed. Natural selection drives microevolution. Microevolution is defined as evolution involving small changes. Microevolution does not require the evolution of new structures or organs, Therefore, microevolution does not involve the creation of new genes. Changes to existing genes (mutations) result in variation. Natural selection acts on this variation and preserves the best. So while the variation may be random, the process of microevolution is not. Natural selection preserves favorable variations at the expense of less favorable variations. This process optimizes existing genes. Natural selection forces animals and plants to adapt. Microevolution happens, and it has been observed in numerous scientific experiments. The real question is not whether or not microevolution happens. It does, but can microevolution be extended to explain large evolutionary 2004-12-29T06:54:20-05:00 http://75.150.148.189/free-essay/Darwinism-Research-Paper-26093.aspx Stem Cell Research One of the most popular clinical studies being researched these days is stem cell transplantation. Until recently, moral issues of states and countries haven't allowed research to expound deeply into the unknowns. Within the last ten years though, scientists have made leaps and bounds in finding out concrete facts that this stem cell research has supplied. Tommy G. Thompson, Secretary of Health Services states, "I believe it will open up a world of opportunity for scientists, not only at the NIH, but elsewhere, because it demonstrates a cooperative atmosphere among academia, the private sector, and government that will allow us to move ahead" ("sign stem"1). New ways of conducting stem cell research have made the healing and repairing treatment for many diverse applications. To prove their point, scientists have broken down the basic facts of their studies throughout the last ten years. Embryonic stem cell transplantation is a related course of cells that are in charge of certain functions and systems of the body. The cells used in the transplantation process are contrived from "cryopreserved suspensions" from the fetal liver, thymus, bone marrow, spleen, brain, and the pancreas. Introducing these cells to the body can be approached in different ways. The first step taken is engrafting or multiplying cells in the affected area. These cells will then supplement missing or declining cells and replace/repair missing functions of the body. Production then commences with considerable amounts of biologically active substances such as nerve growth factor, tumor necrosis factor and interleukins etc. When these cells have been transplanted, they are capable of migrating, establishing intercellular links and responding to various effects. However, because of their immature transplantation to the human body, these cells cause a weaker immune response than mature cells. Alexander Smikodub, a doctor of Medical Science at the National Medical University states, "cells that we use are not considered by the immune system of the recipient as foreign, therefore, they can survive, multiply, and develop full function in the body of a new host" Smikodub). These cells can then survive and multiply, capable of lasting for months and years in the body of the recipient. In the areas where tissue or organs have been damaged or lost, they substitute the lack of functional activities. These cells can also produce new generations of cells that are needed by 2004-12-26T01:02:14-05:00 http://75.150.148.189/free-essay/Stem-Cell-Research--26049.aspx What is Gynecomastia? Definition Gynecomastia is a common disease of the male breast where there is a benign glandular enlargement of that breast at some time in the male's life. It usually consists of the appearance of a flat pad of glandular tissue beneath a nipple which becomes tender at the same time. The development may be unilateral or bilateral. There is rarely a continued growth of the breast tissue; ordinarily the process is of brief duration and stops short of the production of permanent enlargement of the breast. Causes A great number of patients who suffer from this disease have a disturbance in the proper ratio of androgen and estrogen levels. The normal ratio of the two hormones in plasma is approximately 100:1. "The etiology of gynecomastia in patients with a known documented cause appears to be related to increased estrogen stimulation, decreased testosterone levels, or some alteration of the estrogens and androgen so that the androgen-estrogen ratio is decreased"(Williams 373). From this information it was discovered that there is also a lower ratio of weaker adrenal androgens (delta 4-androstenedione and dehydroepiandrosterone) found in youths with this disease. It was once believed that there was an imbalance in the ratios of testosterone to estrogen or estradiol, but this is now know to be untrue. There are three areas the can be attributed to the cause of gynecomastia: physiologic, pathologic and pharmacologic. "Enlargement of the male breast can be a normal physiologic phenomenon at certain stages of life or the result of several pathologic states."(Isselbacher, 2037) In the case of physiologic gynecomastia the disease can occur in a newborn baby, at puberty or at any time in a man's life. In the newborn, transient enlargement of the breast is due to the action of maternal and/or placental estrogens. The enlargement usually disappears within a few weeks. Adolescent gynecomastia is common during puberty with the onset at the median age of 14. It is often asymmetrical and frequently tender. It regresses so that by the age of 20 only a small number of men have palpable vestiges of gynecomastia in one or both the breasts. Gynecomastia of aging also occurs in otherwise healthy men. Forty percent or more of aged men have gynecomastia. One explanation is the increase in age in the conversion of androgens to estrogens in extra- glandular tissues. Drug therapy and abnormal liver functioning 2004-12-22T23:02:08-05:00 http://75.150.148.189/free-essay/A-Detailed-Explanation-of-Gynecomastia-26006.aspx Explain the process of Cellular Reproduction Cellular Reproduction is the process by which all living things produce new organisms similar or identical to themselves. This has to happen because if a species were not able to reproduce, that species would quickly become extinct. Reproduction consists of a basic pattern: the conversion by a parent organism of raw materials into offspring or cells that will later develop into offspring. The reproductive process, whether asexual or sexual always involves an exchange in hereditary material from the parents so that the new organism may also be able to reproduce. Reproductive processes can be categorized into either asexual reproduction or sexual reproduction. Asexual reproduction is any form of reproduction that does not require the union of male and female reproductive material (sperm or egg). Most single celled organisms reproduce by the asexual process known as fission, which is commonly called mitosis. Fission is The splitting of a nucleus into two roughly equal parts accompanied by the release of a pretty large amount of energy. Interphase, the first phase of the cell cycle and also the phase before mitosis, starts as soon as the cell is born. Interphase is broken up into three phases, G1, S, and G2. During the G1 phase, the cell increases in mass except for the chromosomes, which stay the same. Protein synthesis is also occurring during this phase. If a cell doesn't divide further, it remains in the G1 phase. Next is the S phase, in which the mass of the cell continues to increase, and DNA is duplicated, and then the chromosomes divide. During the G2 phase of Interphase, the cell becomes double its mass at birth, the chromosomes begin to shorten and coil, and the centrioles appear, the cell is now ready to enter into mitosis. In the first phase of mitosis, prophase, the chromosomes become visible and the centrioles split in half and then move to opposite sides of the cell. At this point chromosomes have formed into two chromatids separated by a structure called a centromere. Spindle fibers are barely visible. During metaphase, the second phase of mitosis, the two chromatids line up along the equator of the cell. Each chromatid has its own spindle fiber. Next comes the third phase of mitosis, Anaphase, in which the centromeres break in half, causing each of the two chromatids to start to be 2004-12-22T23:01:06-05:00 http://75.150.148.189/free-essay/The-Process-of-Cellular-Reproduction-26005.aspx Biology and Chemical Warfare Introduction Chemical and Biological Warfare, use of harmful or deadly chemical or biological agents as weapons of war. These agents can kill many people and are considered weapons of mass destruction. Chemical weapons are made up of poisonous chemical compounds, whereas biological weapons are living microorganisms. Toxin weapons contain poisonous chemical products of living organisms and are sometimes classified separately. Chemical and biological weapons can cause injury in several ways. Most cause injury or death when inhaled, and some cause injury through contact with skin or through ingestion of contaminated food. A chemical or biological attack usually involves dispersing agents into the air. This can be done in various ways, such as firing artillery shells that burst in mid-air, or using airplanes to spray the agents over an area. If released outdoors, these types of weapons can be affected by weather conditions. Rain would reduce the effectiveness of the agents, and wind might spread them in unexpected directions. Because chemical and biological agents are seen as random, dangerous, and particularly cruel weapons, they have rarely been used. In the 20th century, chemicals were used extensively as battlefield weapons only in World War I (1914-1918) and the Iran-Iraq War (1980-1988). The release of the nerve agent sarin in a Tokyo subway in 1995 was a rare terrorist chemical attack. The 1972 Biological Weapons Convention and the 1993 Chemical Weapons Convention are the most recent international agreements prohibiting these types of weapons, and both have been signed by many countries. Nevertheless, analysts contend that following the Iran-Iraq War, more countries began to secretly develop chemical and biological weapons, and the threat of their use has become greater. Iraq in particular has been accused of stockpiling such weapons, and Iraqi resistance to United Nations weapons inspections in the late 1990s raised international awareness of the need for stronger efforts to control biological and chemical weapons. II. Chemical WarfarePrint section Chemical warfare involves the use of chemical compounds to kill or seriously injure an enemy. Several countries began eliminating their chemical weapons stockpiles in the 1990s, but the threat of their use still exists. A. Chemical AgentsPrint section Chemical warfare agents can be grouped into two general types: those that affect the body surfaces they contact, and those that damage the general nervous system. Walking with Dinosaurs Book The Map That Changed the World: William Smith 2004-12-22T23:00:34-05:00 http://75.150.148.189/free-essay/Biology-and-Chemical-Warfare-Research-Essay-26004.aspx Heart Attack Risk in Women Under 50 Heart attacks are less common in women then men. However, they do occur and when they do women are more likely to die. Women who have heart attacks normally are worse then men who have heart attacks. Age has played a big role in heart attacks. Men who are older, the risk goes up with age. Women's risk of death is the same up to the age of 75 years old. Scientist are still looking into the reason for this. A study showed that 155,565 women and 229,313men that had heart attacks and were treated at 1,658 hospitals showed that younger women are at high risk and need special attention. This research came from The New England Journal of Medicine. Another study was also done, which involved 3,662 women and 8,480 men who all had heart problems. This study also showed that women are more likely to die then men. It also said that women, who were at risk, are more likely to a weakened heart muscle and a very low blood pressure. When they performed an electrocardiogram, the results from this were very heard to tell if the woman was having a heart attack or not. This study also showed that women had more complications from the treatment. One of the complications being that they had bleeding from the blood thing drugs that are usually given to patients who have a history of heart attacks. In women, heart attacks are known to be different from those in men. Blocked arteries are more likely to bring out heart attacks in men. In women, clear arteries were found but yet they were still having heart attacks. It is said that women who were still having these heart attacks were probably caused by spasms in the arteries and large blood clots. In the United States of America, heart disease is the leading cause of death. The American Heart Association says that 9,000 women aging from 29 to 44 had heart attacks in 1997, in comparison to 32,000 men. The American Heart Association also says that 6.1 percent of the women died from a heart attack and were under the age of 50, this was compared with the 2.9 percent of men. Dr. Viola Vaccarino, who is a professor of epidemiology 2004-12-22T22:45:57-05:00 http://75.150.148.189/free-essay/Heart-Attack-Risk-in-Women-Under-50-25998.aspx Kitchen Safety And Sanitation Do you follow the proper safety and sanitation guidelines in your kitchen? You probably think that your kitchen is safe and you're not at risk of food poison. Well, there is a lot more about safety and sanitation that you should know. Microorganisms are tiny living creatures that are only visible through a microscope. Parasites are organisms that get their nutrients from other living organisms. Microorganisms and parasites are everywhere in your kitchen. These are what can cause much food poisoning. You probably think that they don't live in your kitchen because you keep it clean, right? Think again. Have you ever heard of cross contamination? That is when you let microorganisms from one food get into another. Of course, 2004-12-22T22:07:06-05:00 http://75.150.148.189/free-essay/Kitchen-Safety-And-Sanitation-25982.aspx Cloning Of all the terms coined by scientists which have entered popular vocabulary, 'clone' has become one of the more emotive. Strictly speaking a clone refers to one or more offspring derived from a single ancestor, whose genetic composition is identical to that of the ancestor. No sex is involved in the production of clones, and since sex is the normal means by which new genetic material is introduced during procreation, clones have no choice but to have the same genes as their single parent. In the same way, a clone of cells refers simply to the descendants of a single parental cell. As such, adult organisms can be viewed as clones because all their parts stem from the single cell which is the fertilised egg. Likewise, many tumours are clones, derived from one aberrant cell which no longer obeys the normal rules of growth control. The offspring of organisms which reproduce asexually, like corals, are also clones; as are identical twins produced by the natural, or sometimes deliberate, splitting of a single embryo. Members of a clone are genetically identical and genetic identity has given cloning an additional more technical meaning: namely the procedures used to create a new organism whose genetic constitution is a replica of another existing individual. Such a feat can be achieved by substituting the nucleus, which contains the genes, from one of the cells making up that individual's body, for the nucleus of a fertilised egg. Since our genes dictate to a large extent what we look like, how we behave and what we can and cannot do, having identical genes, as identical twins do, ensures something more than mere similarity. Novelists and film makers have not been slow to exploit the imagery afforded by cloning. Limitless numbers of identical beings manufactured from existing or previous generations has obvious dramatic potential, although seldom of a reassuring nature. Clones traverse the cinema screen as crowds of dehumanised humans destined for monotonous drudgery, as invincible armies of lookalikes from outer space, as replicas of living megalomaniacs and, in the ultimate fantasy, as the resurrected dead - troupes of little Hitlers and herds of rampaging dinosaurs. Of course, this is science fiction. Nonetheless there is just a whiff of plausibility, a whisker of scientific credibility; enough to plant an indelible vision of what might be, or even what could be. So it is easy to understand why the arrival 2004-12-22T21:02:27-05:00 http://75.150.148.189/free-essay/Cloning,-Methods,-Controversy,-and-Analysis-Research-Paper-25970.aspx Cochlear Prosthesis Most people in American society prejudge the deaf community’s world without really attempting to understand it. That’s why the so-called “hearing experts” have come up with a device to help deaf children hear and speak. They don’t understand that the deaf culture doesn’t feel a need to speak. Instead they are perfectly content with American Sign Language (ASL) as an adequate and complete way to converse and express themselves. This misunderstanding on the part of the hearing scientific community has resulted in the invention of a device called a cochlear prosthesis. It’s designed to remedy a disability, but I believe it is a major setback to the deaf cultures values. While the hearing people feel that all the deaf should have the desire to speak, the deaf culture itself condemns those that are deaf who insist upon wanting to speak. The deaf see these people as having no pride in themselves. They are strong in their belief that full communication can happen through spoken language and ASL. This is why the deaf are against the implantation of a cochlear prosthesis into young deaf children. They agree it will only cause them to have a false sense of being, and create in them the notion that it’s not O.K. to be deaf. Harlan Lane explains that the implant is a drastic surgical procedure in which a wire is inserted into the inner ear and into the cochlea. This wire transmits electrical signals into the ear with the intent of converting the signals into sound. However, it usually destroys any normal sense of hearing a child may have had previously. It also prevents the child from ever feeling natural again because of the large device installed on their outer ear. There are many risks involved with getting a prosthesis, many of which are still unknown. If you were considering getting a prosthesis for you or your child, would you do so if so under such circumstances’ The normal life of a child who is unfortunate enough to receive one of these implants is drastically interrupted. Up to eight hours a day can be spent on learning how to speak and most of the time this isn’t accomplished because of the poor sound quality of the device. They must endure many checkups throughout their lives to maintain proper functioning of the device. This 2004-12-21T08:09:14-05:00 http://75.150.148.189/free-essay/Cochlear-Prosthesis-Pros-and-Cons-25947.aspx Pellagra Abstract: Pellagra is a nutrient-deficiency disease of major public health importance caused by inadequate intake 2004-12-21T06:51:34-05:00 http://75.150.148.189/free-essay/Pellagra,-a-Nutrient-Deficiency-Disease-25936.aspx The Effects Of Steriods On The Body Drugs have been used in sports almost as long as sports themselves have been around. The ancient Incas discovered that the ashes from burned leaves of the Coca tree gave the people great stores of energy, and made sleep unnecessary for hours or even days, it was later discovered to be the stimulant cocaine. They would take it before long hunts, battles, and even found it useful in ancient sport competitions. It wasn't until 1886 that the first drug-related death in sports occurred. A bicyclist took a mixture of cocaine and heroine, called the “speedball,” and died from it. Little were the doctors aware the epidemic that would follow in the next century. Anabolic steroids, developed in the 1930's in Europe, are drugs that help to build new body tissue quickly, but with drastic side effects. Anabolic means the ability to promote body growth and repair body tissue. It comes from the Greek word anabolikos meaning “constructive.” Steroids are basically made up of hormones. Picture: One woman training to make the 1984 US women's basketball team used them, her muscles started to bulge, her voice grew deeper, and she even had the beginnings of a mustache. These are all the usual symptoms of anabolic steroids. Steroids were not always used for sports, they started out the same way most drugs did, medicinal purposes. Victims of starvation and severe injury profited from it's ability to build new tissue quickly. They also helped prevent muscle tissue from withering in patients who had just had surgery. Steroids are used to treat Addison's disease. Anabolic steroids are drugs that come from hormones or from combinations of chemicals that achieve the same result as hormones. Hormones may be given to an individual in their natural state, or in a synthetic one. The synthetic state is sometimes more potent than the natural one. Testosterone and progesterone are hormones used in steroids, another kind comes from the adrenal glands, which secrete various necessary bodily chemicals. The steroids themselves can be taken orally, as tablets or powders, and can also be liquids that are injected into the muscles. The steroids taken by athletes contain testosterone or chemicals that act in similar way to testosterone. Testosterone is found in men and women, but 2004-12-21T06:46:55-05:00 http://75.150.148.189/free-essay/The-Effects-Of-Steriods-On-The-Body-25933.aspx Title: El Niño Model Lab Purpose: Hands on demonstration of the El Nino effect, trade winds, and upwelling. Materials: • Clear plastic oblong container (approx. 18’’x4’’x4’’, smaller will work, food containers are ideal), • Water, • Mineral oil, • Blue food coloring, • Hair dryer • (Red Oil-based Paint – optional) • Paper sheet map showing the Pacific Ocean Procedures: • Fill the tray with water to within 1’’ of the top. • Add green food coloring to the water until there is a nice “ocean blue”. (Some of the food coloring will settle to the bottom which is fine because this will show the upwelling.) • (Pour some mineral oil in a bowl and mix in some red oil-based paint until the oil is evenly colored. If you do not have oil-based paint, it does not affect the outcome – we don’t’ use it in our demos here). • Gently pour the oil over the surface of the water. (It’s okay if it mixes a bit because it will separate out again.) • Put the container on the paper and mark East and West at either end, Indonesia and South America. • Plug in hair dryer, being careful to keep it away form any water spills. Conclusion: El Niño is a warm current that occurs each year in the month of December. This natural occurrence is the cause of changes over the entire tropical Pacific. When this large phase of warm oscillation happens the surface temperature of the eastern part of the tropical Pacific varies by up to about 4°C and there are also changes in the winds and rainfall patterns. El Niño lasts anywhere from three to seven years and usually includes a cold phase known as La Niña. During the El Niño, trade winds weaken and the piled up water in the west drifts back east, carrying the warm water with it. The most severe effects of El Niño occur near the equator. Indonesia undergoes a pattern of deserts, while Peru receives heavy rainfall. There are forest fires in Indonesia and Australia to an awesome degree, while Peru experiences flooding. In our model, the hairdryer represents the trade winds which blow the warm waters from the east to the west. Because of this, the “warm” water tends to pile up in the West and sediment surfaces at the east end. This sediment upwelling brings nutrient-rich bottom waters to the surface, creating areas which are rich in fish and other sea life. The rising air moves from west to east with the warm pool, and so does the pumping 2004-12-21T06:46:30-05:00 http://75.150.148.189/free-essay/El-Niño-Model-Lab-25932.aspx Coral Reefs Coral reefs are complex and diverse habitat. They are perhaps on of the most interesting and colorful ecosystems to be found in the marine environment. They are very unique in many ways. Coral reefs play many important poles in the marine world. They must have certain conditions to be formed, and to survive. Lots of different sea life rely on reefs for habitat and sources of food, including some endangered species. Coral reefs are perhaps one of the greatest yet least known of wonders of our world. The formation of a coral reef is a long and slow process, taking about a year for a reef to grow about half an inch. Many factors affect the growth of the coral. The general pattern of coral reefs is a continuous cycle of growth and destruction, resulting from the growth of the coral and destructive activities of animals and storms. This pattern serves to keep the coral reef alive and at a fairly constant level. Coral reefs must have certain conditions to survive. They must be in reasonably shallow water. Low levels of sedimentation in the water are very important too, because too many sediments in the water can block the sunlight needed for the coral reefs. Because of the sunlight required for reefs to survive, they can only grow to depths of 45 meters deep. They only form in tropical seas and areas that stay above 20 degrees Celsius. The amount of oxygen is also important. Oxygen is produced in the daytime by plant photosynthesis, but the level drops dramatically at night. Ocean waves and water movement play a part in the amount of oxygen in the water as well, this allows diffusion of oxygen into the surface levels. There are three different kinds of coral reefs. There are fringing, barrier, and atoll. Fringing reefs are attached to margins of an island or continent, rough, table like surface, as much as 1 kilometer wide. On their seaward side they slope steeply to the ocean floor. Fringing reefs grow in shallow water near the shore and prefer dry climates with limited river runoff. There are also barrier reefs, which are similar to fringing but separated from mainland with a lagoon. The number of barrier reefs is greatly increasing due to global warming, because of the rise of the water’s level. Barrier reefs grow best where 2004-12-21T06:39:14-05:00 http://75.150.148.189/free-essay/Research-Paper-on-Coral-Reefs-and-their-Habitat-25930.aspx Title: Water/Penny Lab Purpose: To observe and explain several unique properties of water: cohesion, adhesion, and surface tension. Materials: Water, beaker, pipette (dropper), penny, paper towels. Procedure: 1.Place the penny on the paper towel. Using the pipette, carefully place drops of water on the penny. Observe carefully as you add water. 2.Count the number of drops until the “bubble” bursts. Record the number of drops in a clearly labeled chart. 3.Perform three trials (Repeat steps 1& 2 three times). 4.Calculate the average number 2004-12-21T05:27:49-05:00 http://75.150.148.189/free-essay/Water-and-Penny-Lab-Research-Paper-25912.aspx Title: Chromatography Lab Purpose (Hypothesis): To understand the process of chromatography, and see which color will have the greatest rate of seperation. Materials: Nine drops of blue dye; Fifteen drops of green dye, Twenty seven drops of yellow, Seventy drops of re-orange, 250 ml beaker, Absorbent, Water, Pipette Procedures: Gather Materials  Fill Beaker W with approximately 50 milliliters of water  Fill 2004-12-21T05:23:34-05:00 http://75.150.148.189/free-essay/Chromatography-Lab--25911.aspx Testing for Nutrients in Food Problem/Question: To test for the presence of sugar, starch, protein, and lipids in various food. Hypothesis: Our hypotheses are shown in the prediction section of the chart in which we recorded data. We based our hypotheses on previous knowledge of nutrition content in foods and recent things we learned in class. Theory: A balanced diet is important in everyone's health. It is necessary to eat a variety of foods in order to obtain sufficient quantities of the needed vitamins and minerals, such as sugars, starches, lipids, and proteins. The four food groups help us determine how much of each type of food is necessary in a healthy diet. Materials: · Test tube rack · Test tubes · Beaker · Hot plate · Bunsen Burner · Paper towels · Test tube holder · Goggles Procedure: Sugar Test: For the sugar test we added approximately 5ml of water to a small test tube and then added a small sample of the food to be tested. Then, we added 5 drops of Benedicts reagent and heated this mixture in a beaker on a hot plate or over a Bunsen burner. Yellow or orange was indicative of various levels of sugar content. Starch Test: We took a small sample of the food to be tested and placed 3 drops of iodine on it. If it turned a purple or black then starch was present. Protein Test: We added approximately 5ml of water to a small test tube and then added a small sample of the food to be tested. Then, we added 5 drops of Biuret. If the mixture turned a purple in color then protein was present. Lipid: We applied a small sample of each food to be tested to a brown paper bag. We held the bag up to the light and to see if the bag had become somewhat transparent. If it had, then lipids are present. Data: (see attached) Data Analysis: We found that carrots do not have sugar, starch, protein or lipids. Saltine crackers have minimal sugar have starch but do not have lipids. Boost Nutritional Drink has sugars proteins but lacks starches and lipids. Kudos bars have sugar, proteins and lipids but has no starches. Egg whites have only protein and lipids. Apples have lipids and proteins only. Peanut butter has sugar, protein, and lipids, but no starch according to our tests. Food Test Sugar Test Starch Test Protein Test Lipid Test Prediction Results Prediction Results Prediction Results Prediction Results Carrot YES NO NO NO NO NO NO NO Cracker NO Small YES YES NO NO NO NO Boost YES Simple NO NO YES YES NO NO Kudos YES YES YES NO NO YES YES YES Egg White NO NO NO NO YES YES YES YES Apple YES Lots YES NO NO NO NO YES Peanut Butter YES YES NO NO YES YES YES YES Conclusion: Our hypotheses were correct approximately 75% of the time. This shows that we did have some previous knowledge regarding the nutritional content of the foods we tested. This 2004-12-20T03:53:18-05:00 http://75.150.148.189/free-essay/Testing-for-Nutrients-in-Food-Lab-25857.aspx Adrenoleukodystrophy The full name of ALD is Adrenoleukodystrophy. It is a rare X chromosome sex linked metabolic disorder that is characterized by the loss of myelin on nerve fibers within the brain. Myelin is the fatty covering on the nerve fibers. The disease causes the continued degeneration of the adrenal gland. The basic defect is that the impaired capacity to degrade very long chain fatty acids that are found in the blood plasma and tissues of the body. These fatty acids accumulate in the cerebral white matter of the brain and the adrenal glands. ALD only effects males. The symptoms of ALD may develop due to abnormal or a lack of microbodies that participate in the metabolism of fats called peroxisomes in the liver. This causes a disturbance of fatty acid metabolism and results in the abnormal accumulation of very long chain fatty acids. The exact enzyme deficiency that prevents the breakdown of VLCFAs is not known. ALD is an allelic mutation. The disease is caused by one mutation at the locus Xq28. The mutation causes deficient activity of the ligase enzyme. Diagnosis of the disease can be made from cultured skin fibroblasts or amniotic fluid cells. The disease is preventable through a combination of oleic and erucic acid (as used in Lorenzo’s Oil) and a restricted diet lacking in very long fatty acids. More recently, some ALD patients have been experimentally treated with Glycerol Trioleate. Continued research is being done to determine the effectiveness and safeness of these substances. For those that are identified with the disease prenatally or soon after birth, this is a successful treatment. Those that take the prescribed dose of the oil and are restricted in their diet appropriately can live otherwise normal lives. The Myelin Project is the research project dedicated to the cure of this disease and others related to it. It is supported by many families affected by this disease. They are attempting to hurry science and advance to the moment where myelin can be restored. The Myelin project has branches in Italy, Austria, Canada, Britain, France, Denmark, Spain, Dubai, and Switzerland. The Myelin Project allows researchers to work together effectively in conjunction with those (and their families) affected by the disease(s). Myelin leads to the reduction or blockage of nerve impulse conduction. Thus, regrowing Myelin should restore conduction in diseases for which therapies capable of halting “demyelination” have been found. It could also prove beneficial 2004-12-20T03:52:01-05:00 http://75.150.148.189/free-essay/Adrenoleukodystrophy-what-is-it-An-Explanation-Essay-25856.aspx Cellular Reproduction is the process by which all living things produce new organisms similar or identical to themselves. This has to happen because if a species were not able to reproduce, that species would quickly become extinct. Reproduction consists of a basic pattern: the conversion by a parent organism of raw materials into offspring or cells that will later develop into offspring. The reproductive process, whether asexual or sexual always involves an exchange in hereditary material from the parents so that the new organism may also be able to reproduce. Reproductive processes can be categorized into either asexual reproduction or sexual reproduction. Asexual reproduction is any form of reproduction that does not require the union of male and female reproductive material (sperm or egg). Most single celled organisms reproduce by the asexual process known as fission, which is commonly called mitosis. Fission is The splitting of a nucleus into two roughly equal parts accompanied by the release of a pretty large amount of energy. Interphase, the first phase of the cell cycle and also the phase before mitosis, starts as soon as the cell is born. Interphase is broken up into three phases, G1, S, and G2. During the G1 phase, the cell increases in mass except for the chromosomes, which stay the same. Protein synthesis is also occurring during this phase. If a cell doesn't divide further, it remains in the G1 phase. Next is the S phase, in which the mass of the cell continues to increase, and DNA is duplicated, and then the chromosomes divide. During the G2 phase of Interphase, the cell becomes double its mass at birth, the chromosomes begin to shorten and coil, and the centrioles appear, the cell is now ready to enter into mitosis. In the first phase of mitosis, prophase, the chromosomes become visible and the centrioles split in half and then move to opposite sides of the cell. At this point chromosomes have formed into two chromatids separated by a structure called a centromere. Spindle fibers are barely visible. During metaphase, the second phase of mitosis, the two chromatids line up along the equator of the cell. Each chromatid has its own spindle fiber. Next comes the third phase of mitosis, Anaphase, in which the centromeres break in half, causing each of the two chromatids to start to be pulled to different sides of the cell. The spindle fibers pull 2004-12-12T05:44:28-05:00 http://75.150.148.189/free-essay/Cellular-Respiration--25826.aspx Anti-Cloning Research: To those against it, cloning presents as much a moral problem as a technical problem. For them, cloning is an affront to religious sensibilities; it seems like "playing God," and interfering with the natural process. There are, of course, more logical objections, regarding susceptibility to disease, expense, and diversity. Others are worried about the abuses of cloning. Cloning appears to be a powerful force that can be exploited to produce horrendous results. Their basic objections to cloning research are outlined here. Cloning may reduce genetic variability, Producing many clones runs the risk of creating a population that is entirely the same. This population would be susceptible to the same diseases, and one disease could devastate the entire population. One can easily picture humans being wiped out be a single virus, however, less drastic, but more probable events could occur from a lack of genetic diversity. For example, if a large percentage of an nation's cattle are identical clones, a virus, such as a particular strain of mad cow disease, could effect the entire population. The result could be catastrophic food shortages in that nation. Cloning may cause people to settle for the best existing animals, not allowing for improvement of the species. In this way, cloning could potentially interfere with natural evolution. Cloning is currently an expensive process. Cloning requires large amounts of money and biological expertise. Ian Wilmut and his associates required 277 tries before producing Dolly. A new cloning technique has recently been developed which is far more reliable. However, even this technique has 2-3% success rate. There is a risk of disease transfer between transgenic animals and the animal from which the transgenes were derived. If an animal producing drugs in its milk becomes infected by a virus, the animal may transmit the virus to a patient using the drug. Any research into human cloning would eventually need to be tested on human. The ability to clone humans may lead to the genetic tailoring of offspring. The heart of the cloning debate is concerned with the genetic manipulation of a human embryo before it begins development. It is conceivable that scientists could alter a baby's genetic code to give the individual a certain color of eyes or genetic resistance to certain diseases. This is viewed as inappropriate tampering with "Mother Nature" by many ethicists. Because clones are derived from an existing adult cell, it has older genes. Will the clone's life 2004-11-21T21:42:56-05:00 http://75.150.148.189/free-essay/AntiCloning-Research--25740.aspx Cloning Supporters: Supporters of cloning feel that with the careful continuation of research, the technological benefits of cloning clearly outweigh the possible social consequences. In their minds, final products of cloning, like farm animals, and laboratory mice will not be the most important achievement. The applications of cloning they envision are not nightmarish and inhumane, but will improve the overall quality of science and life. Cloning will help to produce discoveries that will effect the study of genetics, cell development, human growth, and obstetrics. Human cloning is not the issue, it is merely a threat to the continuation of cloning research. Their arguments for such research are displayed here. Cloning might produce a greater understanding of the cause of miscarriages, which might lead to a treatment to prevent spontaneous abortions. This would help women who can't bring a fetus to term. It might lead to an understanding of the way a morula (mass of cells developed from a blastula) attaches itself to the uterine wall. This might generate new and successful contraceptives. Cloning experiments may add to the understanding of genetics and lead to the creation of animal organs that an be easily accepted by humans. This would supply limitless organs to those in need. The growth of the human morula is similar to the growth at which cancer cells propagate. If information derived from cloning research allows scientists to stop the division of the human ovum, a technique for terminating cancer may be found. Cloning could also be used for parents who risk passing a defect to a child. A fertilized ovum could be cloned, and the duplicate tested for disease and disorder. If the clone was free from defects, then other would be as well. The latter could be implanted in the womb. Damage to the nervous system could treated through cloning. Damaged adult nerve tissue does not regenerate on its own. However, stem cells might be able to repair the damaged tissue. Because of the large number of cells required, human embryo cloning would be required. In in-vitro fertilization, a doctor often implants many fertilized ova into a woman's uterus and counts on one resulting in pregnancy. However, some women can only supply one egg. Through cloning, that egg could be divided into eight zygotes for implanting. The chances of pregnancy would be much greater. Cloning would allow a women to have one set of identical twins instead of going through two pregnancies. 2004-11-21T21:42:14-05:00 http://75.150.148.189/free-essay/Pros-of-Cloning-research-25739.aspx This short report will give you a short summary on evolution and how it my affect us, or even surroundings. Also, how it my affect our food chain and if one thing would die how the other would suffer because of that, for an example if you had snakes and birds and if snakes were to die birds population would drop. Why, because birds feed on snakes. Now a part of the food chain contains something called “niche” now you are asking what that is, so I guess that I will answer that question, it basically what the organism will do in the food chain. A food chain is how in the world’s animals, people, parasites, and insects get all of their food ,and what predators will eat them.. Plus, it has to do with how all of the organisms on this earth, and maybe; not to be insulting, but to those who believe in Extra Terrestrial, and how all of these came to our extraordinary planet. But, there is a man by the name of Darwin, a man who I think might believe in God , yes God ,but God of “Thunder” maybe any God but not the one that I think really counts. This DARWIN who is kind of dumb, believed that everything on this earth came from nothing. Now, what Darwin really doesn’t know is how nothing came from nothing. What they call people who believe in this dumb theory are called Darwinist. So I guess you could call these people pessimist or at least him. On the other hand there are people who believe in what you, me, and almost all of the “intelligent” people would believe in these people are called creationist. Are creationist believe that there were things that put this nothing on the earth. Now since this is creative writing, I can not understand how people can tolerate this nonsense on how there was nothing and how it created Dinosaurs etc… So in a way he did kind of believe in evolution he just could not understand that animals came from a creator and not from a particle. If you were to take your imagination, picture being in a food chain. Now everybody know that humans don’t eat human in the “present day” but if humans were in the food chain and we did not have a Martins’ or a 7UP we would 2004-10-30T05:24:15-04:00 http://75.150.148.189/free-essay/Evolution--25642.aspx My brother was studying for his biology test. The next morning he was telling me about the dream he had. He said he traveled through a cell. I started to call him insane. My brother have an educational dream? I thought to myself, impossible. My brother started to tell me his crazy dream. The first place he came upon was the cell wall. He was trying to find a way out. He said he started to talk to the cell wall. He asked the cell wall the way out. The cell wall said to him “How should I know? I’m the outer most part of the cell all I do is make cellulose. You might want to ask the cell membrane she is right next to me.” He told me he didn’t have to walk far to get to the cell membrane. He described the inside of the cell membrane. He said he saw parts flying in and out of there. Kind of like an assembly line. He asked the cell membrane the way out. The cell membrane just replied “ How should I know? I’m an envelope that engulfs the cell which permits a passage of materials into and out of the cell. I’m very thin and flexible. You might want to ask the chloroplast.” He went on with the story by walking to the chloroplast. He asked the chloroplast the way out here. The chloroplast just said, “ I have no idea.” Will you stop bugging me I’m trying to work?” “What’s your job” my brother asked. The chloroplast replied, “ I help with the photosynthesis process by providing chlorophyll. If you want to get out of here ask the mitochondria.” As my brother was on his way to the mitochondria he saw a small round structure that looked like a bean. My brother asked, “What are you and what job do you do?” “I’m a lysosome I help in the digestive activities of the cell.” My brother asked her do you know where the mitochondria? The lysosome replied, “ of course he is right over there.” My brother started to walk that way. He asked the mitochondria the way out. The mitochondria said “ I don’t know all I know is how to do my job.” “What’s your job?” my brother asked. The mitochondria replied in a deep tone, “I’m the powerhouse of the cell in which 2004-10-30T05:21:34-04:00 http://75.150.148.189/free-essay/Biology-Test-Cells-25641.aspx Photosynthesis is process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose. In so doing, photosynthesis provides the basic energy source for virtually all organisms. An extremely important byproduct of photosynthesis is oxygen, on which most organisms depend. Photosynthesis occurs in green plants, seaweeds, algae, and certain bacteria. These organisms are veritable sugar factories, producing millions of new glucose molecules per second. Plants use much of this glucose, a carbohydrate, as an energy source to build leaves, flowers, fruits, and seeds. They also convert glucose to cellulose, the structural material used in their cell walls. Most plants produce more glucose than they use, however, and they store it in the form of starch and other carbohydrates in roots, stems, and leaves. The plants can then draw on these reserves for extra energy or building materials. Each year, photosynthesizing organisms produce about 170 billion metric tons of extra carbohydrates, about 30 metric tons for every person on earth. Photosynthesis has far-reaching implications. Like plants, humans and other animals depend on glucose as an energy source, but they are unable to produce it on their own and must rely ultimately on the glucose produced by plants. Moreover, the oxygen humans and other animals breathe is the oxygen released during photosynthesis. Humans are also dependent on ancient products of photosynthesis, known as fossil fuels, for supplying most of our modern industrial energy. These fossil fuels, including natural gas, coal, and petroleum, are composed of a complex mix of hydrocarbons, the remains of organisms that relied on photosynthesis millions of years ago. Thus, virtually all life on earth, directly or indirectly, depends on photosynthesis as a source of food, energy, and oxygen, making it one of the most important biochemical processes known. Plant photosynthesis occurs in leaves and green stems within specialized cell structures called chloroplasts. One plant leaf is composed of tens of thousands of cells, and each cell contains 40 to 50 chloroplasts. The chloroplast, an oval-shaped structure, is divided by membranes into numerous disk-shaped compartments. These dislike compartments, called thylakoids, are arranged vertically in the chloroplast like a stack of plates or pancakes. A stack of thylakoids is called a granum, the grana lie suspended in a fluid known as stroma. Photosynthesis is a very complex process, and for the sake of convenience and ease of 2004-10-30T04:00:26-04:00 http://75.150.148.189/free-essay/Process-of-Photosynthesis-25628.aspx The Human Genome Project began in 1990 in the United States as an attempt to identify all of the genes in a human cell. While the U.S. began its efforts in the 90’s, many countries including France, Germany, Japan, and the United Kingdom started programs in an unofficial collaboration to speed up the process. In addition, private companies including Genomics and Celera are currently working on sequencing the human genome. There is an estimated 140,000 genes in the nucleus of a human cell. As of the year 2000, the Project had mapped more than 9,000 genes to specific chromosomes and was already ahead of schedule with 17% completed. The Program had also finished sequencing the complete genome of human chromosome 22 in addition to complete organisms, such as E. Coli (Escherichia coli), yeast (Saccharomyces cerevisiae), the roundworm (Caenorhabditis elegans), and the fruit fly (Drosophila melanogaster). The purpose of sequencing the genes of other organisms would be to determine any possible similarities between their genes and human genes. The Project has already determined the specific genes associated with cystic fibrosis, muscular dystrophy, Huntington’s disease, neurofibromatosis, and retinoblastoma. A popular analogy is used to explain the relationship between chromosomes, DNA, and genes. In a library, or a human body, there are 46 books, or chromosomes. 23 of the books are from your mother, the egg, and the other 23 books are from your father, the sperm. The chromosomes are made up of a coiled chain of DNA, short for deoxyribonucleic acid. The DNA is composed of smaller segments called genes. The genes are the words in the book. The genes are made up of letters called nucleotides. There are four letters, A (adenine), T (thymine), C (cytosine), and G (guanine). On the strand of DNA, each nucleotide matches up with another. Adenine pairs with thymine; and cytosine pairs with guanine. The genome project hopes to sequence the order of these nucleotides. The sequence of the genes is what makes us what we are. They code for height, hair color, and even genetic diseases. The purpose in determining the order is to assist in curing genetic diseases by creating treatments and medicines, correcting fatal errors in the genetic code, and to have an overall better understanding of the human body. 2004-10-29T22:21:45-04:00 http://75.150.148.189/free-essay/Genome--25609.aspx Few scientific achievements of the twentieth century in the field of biology have as much significance as the completion of the Human Genome Project. Completed almost fifty years after the discovery of the DNA double helix and two years after the cloning of Dolly the sheep; no one, just a few years ago would be guessed that in a few short years we would have a complete documented human genome. A genome is all the genetic material in any given organism. The purpose of the Human Genome Project was to document a complete human genome. Every human cell contains a nucleus in which chromosomes are stored. Humans have twenty-three chromosomes. Twenty-two are autosomes, which are responsible for all the inherited characteristics of an organism and one is a sex chromosome. Each cell had two pairs of these chromosomes one from each of its parents. The two sex chromosomes determine the sex of an organism XX being female and XY being male. Genetic material is stored in the form of Chromosomes in the nuclei of cells. Each chromosome contains thousands of genes. Every snippet of genetic information is programmed into a DNA double helix with only the four nucleotides of adenine, cytosine, thymine, and guanine. The final result of the Human Genome Project was a many thousand page book of all the DNA in one human being. The code for DNA is organized into three nucleotide segments, which code for one of twenty different amino acids. The point of DNA is to code for proteins and enzymes, which are both made up of amino acids. Therefore, one strand of DNA can program for one protein, interesting as well because it takes protein to create DNA. One interesting thing scientist discovered during this process was that a large amount of DNA seemed dormant and was unused; scientists are still trying to figure out the point of this seemingly excess DNA. The US Department of Energy started the Human Genome Project in 1990 but due to the slow pace private industry started their own project and a race ensued between them for a rough draft of the human genome. The private industry project finished only marginally before the governments and both are vowing to put this information to good use. The cells were taken from a variety of different races and their results will be compared so they can research any discrepancies. This all seems to 2004-10-29T11:17:51-04:00 http://75.150.148.189/free-essay/Human-Genome-Project--25597.aspx Outline the factors that are responsible for vegetation change over time Vegetation develops in many different and varied environments with each environment having different effects on the vegetation change over time. This essay will examine these different factors, in different environments. It will examine different sereal stages in different environment, the lithosere or rock environment, the psammosere or sand environment, the halosere or saltwater environment and hydrosere or fresh water environment. A sere is a stage of events by which the vegetation of an area develops over time. This begins with the pioneer community and end with the climatic climax vegetation. The first plants to colonise an area are called the pioneer community. The climatic climax vegetation is when the ultimate vegetation development has taken place and the environment has reached equilibrium e.g. when the natural vegetation has reached a stable balance with the climate and soil of an area. As an environment goes through more sereal stages the number of species of plants will increase as will their height. The island of Krakatoa in the Sundra strait between Java and Sumatra is a volcanic island, which erupted in 1883. Its development was rapid only taking twenty-five years to develop from the pioneer community to climatic climax vegetation because of the high humidity and temperatures and the rapid weathering of the volcanic rock. The diagram below shows the way an environment such as Krakatoa develops. There are two types of sereal succession primary and secondary. Primary sereal succession occurs on a new or previously sterile land. It occurs in four different types of environment lithosere, psammosere, halosere and hydrosere. A lithosere is a rock environment. These are initially colonised by blue-green bacteria, which are completely self-sufficient. Therefore the pioneer community is the mosses and lichens which are capable of living in areas which lack soil. The lichens and mosses help to weather the rock along with other types of weathering. This along with the decayed matter of mosses and lichens helps to form a veneer of soil, which can support more advanced plant life. Seeds usually of grass then colonise this soil as time passes the grasses will give way to fast growing shrubs which in turn will be replaced by fast growing trees. Finally these will face competition from slow growing trees such as ash and oak. Although each stage of the succession has been superseded the vegetation from each previous sereal 2004-07-05T22:52:04-04:00 http://75.150.148.189/free-essay/Outline-on-Factors-for-Vegetation-Evolution-Over-Time-25526.aspx All the nutrients the body needs can easily be obtained from a vegetarian diet. In fact, research shows a vegetarian diet can be healthier that that of a typical meat eater. Nutrients are usually divided into five classes: carbohydrates, proteins, fats and oils, vitamins and minerals. We also need some dietary fibre and water. All are needed in varying quantities, from about 250g of carbohydrate per day to less than two micrograms of vitamin B12. Most foods contain a mixture of nutrients, but it is convenient to classify them by the main nutrient they provide. Girls aged 15-18 years need around 45g of protein a day (more, if very active or lactating) and boys aged 15-18 need about 55g (more if very active). Too much protein may aggravate poor or failing kidney function. Vegetarians obtain protein from four main sources: - Nuts and Seeds - Peas, Beans and Pulses - Grains and Cereals - Dairy and Eggs The humble Soya bean is an excellent source of vegetarian protein and is found in veggie bacon, tofu, pot noodles, sausages and sauces! It can be made into milk and other dairy substitutes for vegans. It is also consumed widely by omnivores as soya is found (as a bulking agent) in 70% of processed foods. It is maintained by some that it is necessary to 'combine' the proteins in a vegetarian diet to obtain an adequate supply of amino acids, eight of which are essential for adults and nine for children. Vegetarian proteins are usually deficient in one of the eight essential amino acids, so some people advise that we combine the proteins we eat in a meal or throughout the day to achieve a full complement. Any two of the protein groups in the diagram above can be combined to achieve a full complement of protein. Meals such as beans on toast, or cereal and milk are excellent examples of how proteins can be easily combined to create the full complement of amino acids. The latest research suggests that the body has a short term pool of amino acids and, because of this, we don't have to worry about complementing amino acids at every single meal, as long as our diet is varied and well-balanced. Even foods not considered to be very high in protein are adding some amino acids to this pool. Carbohydrates give us energy. There are three main types of carbohydrates: simple 2004-07-05T22:48:50-04:00 http://75.150.148.189/free-essay/Efficacy-of-Vegetarian-Diets-25523.aspx What is Cardiovascular Disease? How may it be prevented and to what extent is heart transplant surgery a sensible solution to the problem of Coronary Heart Disease? Cardiovascular Disease, or CVD, is Britains biggest killer, responsible for 40% of premature deaths in Britain. CVD is a comprehensive term for several afflictions of the cardiovascular system - the heart and blood vessels of the body. These afflictions are Coronary Heart Disease (CHD), Atherosclerosis and arteriosclerosis, Angina, Coronary Thrombosis and Myocardial Infarction and Stroke. Apart from the high mortality rate - it is estimated that CVD kills 140,000 people a year under 75 years old, chronic heart disease causes incapacitation, suffering and pain in many of it's victims. Much heart disease is also self-inflicted and therefore avoidable. Atherosclerosis and Arteriosclerosis The underlying cause of CHD, strokes and other diseases of the blood vessels is usually atherosclerosis. Atherosclerosis is caused by the build up of cholesterol and other fatty substances in walls of arteries. Firstly the deposits form small streaks on the endothelium of the artery, but gradually build up to form patches known as atheromatous plaques. The deposit is called an atheroma and causes the arterial walls to thicken, hence narrowing the lumen of the artery. The onset of an atheromatous plaque may be caused by some physical damage to the artery, sometimes caused by high arterial pressure - hypertension. Smooth muscle cells proliferate at the site of damage and then lipids and cholesterol are deposited from the blood. The cholesterol deposited in the walls may be attacked by free radicals released by phagocytes which may slow down the passage of low density lipoproteins which carry cholesterol back into the blood with the result of increased deposition of cholesterol. Atheromatous plaques roughen the lining of the artery and disturb the flow of blood, which can stimulate the formation of a clot known as a thrombus. When blood comes into contact with fatty and fibrous tissue, platelets stick to the roughened surface and release clotting factors called thromboxanes. In healthy arteries the amount of thromboxane and prostaglandin is balanced, but in damaged arteries the balance is upset because the endothelial cells lining the artery are damaged so blood clots form. This can block the blood vessel it is forming in, or small pieces known as emboli can break off and travel through the blood vessels and jam at any narrow point in the system, causing a restriction of blood flow to 2004-07-05T22:48:08-04:00 http://75.150.148.189/free-essay/Cardiovascular-Disease-Research-Paper-25522.aspx Mendelian Genetics Gregor Mendel was an Augustinian nineteenth century monk who, due to a series of momentous experiments, is now widely regarded as the forefather of genetics. Mendel studied the inheritance of seven contrasting characteristics of the species Pisum sativum, more commonly known as the garden pea. Each of the variables that Mendel experimented with were discontinuous; there were no intermediate forms. For example, one of the variables was length of stem, which was always either tall or short. From his experiments Mendel was able to draw solid conclusions about the inheritance of characteristics in organisms. With the advancements in genetics since his time we are now able to explain Mendel's principles in terms of chromosomes and genes. Understanding of these exact terms did not exist in Mendel's lifetime. However, Mendel's principles still form the basis of modern day genetics. In his first series of experiments Mendel allowed Pisum to self-fertilise for several generations, so that he knew that these pea plants were purebred. He then cross-fertilised plants which were purebred for contrasting characteristics. For example, he crossbred pure-bred dwarf Pissum with pure-bred tall Pissum. He carried out reciprocal crosses. Even though these plants obviously showed many characteristics he only looked at one characteristic at a time. In collecting the results of his experiments, Mendel recorded the numbers of individuals in each class in the progeny, this established the ratios of the contrasting characters of many subsequent generations. In the F1 generation all the plants were tall. Mendel then left the F1 generation plants to self-fertilise. In the F2 generation there were both tall and dwarf plants in an approximate ratio of 3:1. The same ratio was found in the F3, F4, and F5 etc. generations. Mendel realised that because the 'dwarf' characteristic had disappeared in the F1 and had then reappeared in the F2, the controlling factor for 'dwarf' had remained intact and undiluted from one generation to another. It is never expressed, however, in the presence of a factor for 'tall'. He understood that there must be two independent factors for 'dwarf' and 'tall'. Mendel comprehended that the 3:1 ratio was the product of the binomial expression derived from randomly combining two pairs of unlike elements. We now know Mendel's 'factors' to be genes found on homologous pairs of chromosomes in the nucleus of the cell. There are two or more forms of each gene known as alleles. In Mendel's experiments 2004-07-05T22:45:42-04:00 http://75.150.148.189/free-essay/Mendelian-Genetics--25519.aspx Man has had many far-reaching effects on the environment over the years. Global warming, pollution and the damage to the ozone layer are a few of the major things that can be heard about in the news. Man has damaged the earth gradually over the years and this damage cannot be reversed, we are now trying to stop any more damage being caused to the environment. For example, hedgerows have been destroyed but now people have realized what effects this is having on the environment the government are paying farmers to replant them instead of fencing. Not all of man's effects on the environment are harmful some are beneficial. Conservation work is going on across the country and this is helping to preserve the wildlife and countryside that we have left. The expanding human population has placed a huge demand on the food production of the country. The resources are limited but the population is increasing quite rapidly so the problems are growing. The demand for food means that crops need to be perfect so the use of fertilizers and herbicides is increasing too. One of the problems in the countryside affecting the environment is the disposal of effluent and other pollutants. The main type of waste that we have to dispose of is organic effluent particularly from farms and sewage works. This is disposed of in several ways, the main one being pumping it into the sea and rivers around the country. In more recent years sewage recycling plants have been developed to reuse the water in the waste. Water treatment works are used to treat the waste before it is pumped into the river or sea. The disposal of the waste is accomplished in several ways. Direct removal into a stream or lake is the most commonly used means of disposal. In parts of the world that are faced with worsening shortages of water for both domestic and industrial use, authorities are reusing appropriately treated wastewater for, irrigation of non-edible crops, industrial processing, recreation, and other uses. In one such project, the Potable Reuse Demonstration Plant in Denver, Colorado, the treatment process uses normal primary and secondary treatment followed by lime clarification to remove suspended organic compounds. During this process, an alkaline state is created to improve the process. In the next step, re-carbonation is used to bring the pH level to neutral. Then the water is filtered through several 2004-07-05T22:44:10-04:00 http://75.150.148.189/free-essay/Man-s-Effect-on-the-Environment-25518.aspx Introduction Chromatography is a common technique used by biochemists in separating and identifying different amino acids and helps to reveal the function of cell organelles. Chromatography is particularly approved for its accuracy in distinguishing between each compound, which it does by separating the chemicals according to their Relative Molecular Mass (RMM). The term was introduced in 1906 by Mikhail Tswett and is derived from the Greek words 'chroma´, meaning colour and 'graphein´, meaning to draw. The most popular type of chromatography employs either absorbent paper, or a dried, thin layer of powder on a glass or plastic base. There are 20 naturally occurring amino acids. The generalised structure of an amino acid is NH2CHRCOOH. This consists of an amine group (NH2), carboxylic acid group (COOH) and a distinctive R group bonded to the ?-carbon atom. The R group (or 'side chain´) varies in size, shape, charge, hydrogen bonding, capacity and chemical reactivity. The simplest structure is glycine, which has only an extra hydrogen atom in the side chain. Proteins consist of long chains of amino acids which are held together by chemical linkages called peptide bonds In this experiment, albumen will be used as the chosen protein. Albumen is globular and has a simple structure. Trypsin will be added (the enzyme functioning in the hydrolysis reaction) to the test tube and it will be given a 24 hour incubation at the ideal temperature of 30oC. The trypsin should then have broken up all the albumen into the separate amino acids. Aim To separate and identify a mixture of amino acids by paper chromatography. Method Cut a piece of chromatography paper to about 25cms in length and place on a clean surface. To avoid contamination, hold the paper at the top and wear plastic gloves throughout the whole experiment. Draw a line in pencil three centimetres from the bottom of the paper and then four marks lightly along the line at four centimetre intervals. Using a micropipette, take the prepared albumen from the test tube and lightly dot a small amount on each pencil mark The paper should then by wafted swiftly over a blue flame to speed evaporation. This process should then be repeated 40 times, applying the same amount of albumen to the same area, to build up a concentration. This is necessary for the chromatogram results to be clear and distinct. Always remain standing and be careful with the evaporation process, as it is very easy for the 2004-07-05T22:43:06-04:00 http://75.150.148.189/free-essay/Identification-of-amino-acids-by-chromatography-lab-25517.aspx A HIV particle approaches and attaches to a lymphocyte. (Lymphocytes, which include helper T cells and killer T cells, are small white blood cells that are critical in immune defense and are HIV's principal target.) In order to replicate itself, an HIV particle must get its RNA, which is the genetic blueprint for a new particle, inside the host cell. To do that, the viral particle must first bind to two chief receptors on the outside of the host cell, much like a key fitting into a lock. If even one of those receptors, which are known as CD4 and CCR5 receptors, is missing, the viral core containing the RNA will not get into the cell. (Researchers have found that some AIDS patients, known as long-term non-progressors because they are HIV-positive yet show few or no symptoms of the disease, are missing the gene for one of these receptors.) The binding process is facilitated by a molecule on the surface of the HIV particle called gp120 (for glycoprotein with a molecular weight of 120). Once the viral particle has successfully binded to the host cell, its core can pass through the cell wall into the cell's cytoplasm. The core then dissolves, leaving the RNA and catalyzing enzymes ready to begin the process of replication. Viral RNA transforms itself into double-stranded DNA, and then integrats into the host cell's DNA in order to produce new viral RNA. Once inside the host cell, the viral RNA migrates toward the nucleus through the cell's cytoplasm and eventually through the nuclear membrane. A series of steps that ultimately ends in a new HIV particle follows. First, through a process known as reverse transcription, the enzyme known as reverse transcriptase catalyzes the formation of double-stranded viral DNA using the single-stranded viral RNA as a template. Employing other enzymes such as integrase (shown by the starburst in step 4 and in the graphic at right above), the new viral DNA then breaks open the host cell's DNA and integrates itself into it. This leads to the formation of a new viral RNA strand, which migrates out of the host's DNA. The new viral RNA moves into the cytoplasm, where new viral proteins are built using the viral RNA as a blueprint. A new viral particle is assembled and then migrates out of the host cell to infect new cells. Once the viral protein parts have been built, they are assembled into 2004-07-05T22:41:20-04:00 http://75.150.148.189/free-essay/HIV-Life-Cycle--25513.aspx Exotic diseases are one of the greatest threats to humanity. In a world where so many things are overlooked, diseases and epidemics are clearly overlooked and underestimated far more than any threat of nuclear war, global warming, or any comet headed for earth. Throughout history epidemics have plagued the earth several times resulting in a devastating number of deaths. In this new millennium, many new and old diseases await humanity. What the world doesn't comprehend is that an epidemic can be easily spawn off by many other problems humanity faces today. Some of those problems are high population density, newly inhabited areas, increased travel, new generation without immunity, mutation in microbes, over use of antibiotics, poverty/poor sanitation, and change in human activities. Diseases come into existence, change, and vanish, but some have always been with us. An epidemic attacks a population, it and runs its course, and then dies out, claiming hundreds to thousands of lives. There are ways of preventing some epidemics from starting, but not everyone agrees with the terms. Thus, these prevention plans for some diseases fail. Humanity is faced with many dangers of a doomsday in the next millennium, but the one that seems the most likely to happen is a world epidemic. Pg. 2 Human activities and behavior often help increases the risk of a world epidemic. In such activities like increased travel, shipments of resources and wild animals increase the possibility of catching a deadly virus and starting to spread an epidemic. Human behavior such as neglect can determine the fate of a world epidemic. Most people believe that Ebola or any other exotic disease would spawn off and epidemic only in third world countries, but that´s not true. In 1989 Ebola made it´s way to the United States. The virus hit Virginia, but luckily only in some Monkey´s. The monkeys were shipped in from West Africa, for experiments. What most people didn´t realize right away was that some of the monkeys were infected with Ebola. When the monkey´s arrived, the World Health Organization had found some dead, and diagnosed them with Ebola. The military had to quarantine and then kill all 400 monkey´s before the virus could start an epidemic in the United States. They were lucky they found some of the monkey´s dead and quickly knew from the way they died what from, if the monkey´s were still in the early stages of 2004-07-05T22:40:33-04:00 http://75.150.148.189/free-essay/Exotic-Diseases--25512.aspx The nature of all aquatic environments depends upon the following factors which exert their effects in varying degree: i) The depth of water Has an important secondary effect by reducing the penetration of light and hence the degree of colonization by plants. ii) Light Water absorbs light of long wavelengths, particularly the blue part of the visible spectrum. Since this would not normally be sufficient for photosynthesis, many freshwater plants possess adaptations so that light does not become a limiting factor in their growth. iii) Substrate Streams that carry a large amount of sediment in suspension (e.g. due to a muddy stream bed) may have a decreased amount of light available to submerged aquatics. A muddy stream bed may also pose problems to the attachment or respiration of animals, and can lead to a build up of semi decomposed organic matter. This can lead to a high biological oxygen demand (BOD) and the water becoming anoxic, killing off most life. iv) Temperature Water possesses certain thermal properties which make it a unique environment. In particular, it has a high specific heat, high latent heat of fusion and the highest known latent heat of evaporation. The combination of these properties explains why temperature variations occurring in water are less than those on land. Moreover, when they occur, they take place far more slowly. Most aquatic organisms are well able to tolerate the normal range of temperature variations that occur throughout the year and are known as eurythermous. Species with a narrow temperature tolerance (stenothermous) tend to be restricted in their distribution to particular habitats such as the sources of mountain streams, where the temperature of the water changes little throughout the year. Another important physical feature of water is that it achieves its maxiumum density at 4°C. Above and below this temperature it expands and therefore becomes lighter. This accounts for the fact that deeper waters never freeze solid in cold weather - an important consideration for the animals that live there. v) Availability of Oxygen Freshwater contains significantly less oxygen than air, causing aquatic animals to need to move much more of the surrounding medium than land organisms, to extract the equivalent oxygen. The availability of oxygen relates closely to the development of gills and other respiratory organs. Some burrowers in mud, such as the lavae of some Diptera make use of respiratory pigments like haemoglobin which aid oxygen uptake, indicating the degree of adaptation to anaerobic conditions. Fast flowing water, because 2004-07-05T22:39:53-04:00 http://75.150.148.189/free-essay/Fresh-Water-Ecology-25509.aspx Succession is "A sequence of ecological changes in an area whereby one group of plant or animal species successively gives way to another, culminating in a climax community." This succession occurs in a number of sereal stages. A sere is a stage in a sequence of events by which succession occurs. The complete chain of seres is called a prisere. It begins with a pioneer community and ends with a climax community. This climax community occurs when the ultimate vegetation has become in equilibrium with the local environment. There are four main areas where succession occurs rocky environment called a lithosere, sandy environment called a psammosere, a fresh water environment called a hydrosere and a salt-water environment called a halosere. Two examples of a litosere are Sutsey a newly, formed volcanic island and Krakatoa an island striped of all its vegetation by a series of volcanic eruptions. Sutsey is located to the south east of Iceland and is slowly becoming colonised. The first colonisers of the bare rock on a lithosere environment are blue-green bacteria and single cell photosynthesisers, both of which have no need of a root system. Blue-green bacteria are autotrophs producing their own food through photosynthesis. The presence of blue-green bacteria along with weathering processes help to break up soil creating a very thin soil layer. More advanced plant life can then be supported in this thin soil. Once this plant life dies it rots down to create a humus layer to the soil. This humus layer is then capable of supporting grass seeds. As time progresses the grass species will give way to more dominant species such as small shrubs which in turn will replaced by relatively fast growing trees such as rowan. Eventually these trees will face competition from slow growing trees such as ash and oak. Sutsey however is unlikely to ever reach this climax community due to its frequent salty spray, storms and low temperatures for much of the year. Krakatoa however has reached its climax community with eight hundred different species being recorded in 1983 one hundred years after the clearance of the island. Psammoseres occur in a sandy environment. An example of this is Camber Sands, which has developed over time from a small beach to a complete dune system. The pioneer community in a psammosere is usually lyme grass, sea twitch and marram grass that begin to initiate dune development. These plants hold 2004-07-05T22:37:37-04:00 http://75.150.148.189/free-essay/Ecological-Succession-25508.aspx Creutzfeldt-Jakob disease: Rare fatal degenerative disease of the central nervous system. Creutzfeldt-Jakob disease occurs throughout the world at an incidence of one person in a million; however, among certain populations, such as Libyan Jews, rates are somewhat higher. The disease commonly arises in adults between the ages of 40 and 70, although some young adults have been stricken with the disease. Both men and women are affected equally. The onset of the disease is usually marked by vague psychiatric or behavioral changes, which are followed within weeks or months by a progressive dementia that is often accompanied by abnormal vision and involuntary movements. There is no known cure for the disease, which usually proves fatal within a year of the onset of symptoms. Creutzfeldt-Jakob disease was first described in the 1920s by two German physicians, Hans G. Creutzfeldt and Alfons M. Jakob. It is similar to other neurodegenerative diseases such as kuru, a human disorder, and scrapie, which occurs in sheep and goats. All three diseases are types of transmissible spongiform encephalopathies, so called because of the characteristic spongelike pattern of neuronal destruction that leaves brain tissue pitted with holes. It is this deterioration that causes progressive loss of mental functioning and motor control. The cause of the neurodegeneration has been the topic of much debate. In the 1960s researchers demonstrated that the disease was transmissible from humans to animals. The disease-causing agent was thought to be a slow virus--i.e., a virus that is incubated within the body for years without causing symptoms. Subsequent evidence suggested that Creutzfeldt-Jakob disease, as well as other spongiform encephalopathies, is not caused by a virus but by an unusual pathogenic agent called a prion. A prion is a deviant form of a normally harmless protein found in the brains of mammals and birds. As prions replicate--by converting normal forms of the protein into their abnormal shape--they build up within nerve cells, causing neurodegeneration. Although Creutzfeldt-Jakob disease can be acquired through infection with the prion protein, all but 1 percent of cases are either inherited or sporadic (i.e., occurring at random). Sporadic forms account for the majority of cases of the disease--between 85 and 90 percent. In these cases it is unclear what molecular process causes the aberrant protein to appear in the first place. Researchers speculate that the protein may arise from a mutation incurred as the body ages or as a result of a spontaneous conversion in 2004-07-05T22:36:43-04:00 http://75.150.148.189/free-essay/Creutzfeldt-Jakob-Disease-25506.aspx Actions and Effects of Creatine Throughout time, humans have had a fascination with being excellent at what they do, and athletics have been no exception. Many substances exist, and many have been criticized and analyzed for their safety, legality, and morality for athletes. With the banning of steroids from competitive sports, and the implementation of random drug testing in most sports, most athletes, professional, recreational, and would-be professionals are hoping to gain an edge. More recently, one such edge has been discovered, and it has found itself in locker rooms across the country, in the hands of these athletes, and all the while, and probably more importantly, in the media's direct line of fire. Although legal, creatine has it's proponents and it's opponents, through this paper, I'll discuss some of the factors that make creatine such a hot topic in sports and the health industry. To understand why people use creatine, we must first understand what it is. Creatine is a naturally occurring nutrient that is found in the body (Sahelian, 2000). It is also found in meat and fish, usually at a concentration of about 4 grams of creatine per kilogram (Sahelian, 2000). As a general fact, we consume around 1 gram per day from out daily diet. Vegetarians have a much lower intake of creatine than most meat eaters, and will usually have a noted reaction to creatine supplementation due to this fact (Sahelian, 2000). To apply creatine to the muscle building process, we must understand what it does. When we use our muscle everyday for any activity, we use oxygen to make energy. This energy is created by breaking down a chemical that exists in our body known as adenosine triphosphate (ATP), into another chemical, adenosine diphosphate (ADP), but using oxygen to make energy is a very slow process (Sahelian, 2000). This is the part of the process where creatine makes itself known. Current studies show that creatine supplementation can increase the amount of creatine in muscles, which in turn, speeds up the ATP refueling process (Murphy, 2000). This enhances performance by producing more energy for brief, high-intensity exercise such as sprinting, and allowing for more strenuous workouts (Gutfeld, 1997). All of these factors are crucial to athletes who are searching for their legal "magic bullet". Creatine was first discovered by a French scientist in 1832 (Bamberger, 1998). This scientist discovered a naturally occurring organic compound that could 2004-07-05T22:34:57-04:00 http://75.150.148.189/free-essay/Actions-and-Effects-of-Creatine-25504.aspx A balanced diet is one that provides an adequate intake of energy and nutrients for maintenance of the body and therefore good health. A diet can easily be adequate for normal bodily functioning, yet may not be a balanced diet. An ideal human diet contains fat, protein, carbohydrates, vitamins, minerals, water and fibre all in correct proportions. These proportions vary for each individual because everyone has different metabolic rates and levels of activity. Malnutrition results from an unbalanced diet, this can be due to an excess of some dietary components and lack of other components, not just a complete lack of food. Too much of one component can be as much harm to the body as too little. Deficiency diseases occur when there is a lack of a specific nutrient, although some diet related disorders are a result of eating an excess. An adequate diet provides sufficient energy for the performance of metabolic work, although the energy food is in an unspecified form. A balanced diet provides all dietary requirements in the correct proportions. Ideally this would be 1/7 fat, 1/7 protein and 5/7 carbohydrate. Energy is provided by carbohydrates, fats and proteins. Proteins are a provider of energy in an emergency, but are primarily used as building blocks for growth and repair of many body tissues. These energy providing compounds are needed in large quantities in our diet so are described as macronutrients. We also need much smaller amounts of other nutrients, such as vitamins and minerals. Because much smaller quantities are needed for a balanced diet these are known as micronutrients. Despite the small quantities needed these are essential to provide a healthy diet as they have specific roles in metabolic reactions and as structural components. Within the cells of our body, the nutrients ingested are converted to other compounds which are then used for metabolism and other cellular reactions. Starch, a major carbohydrate is converted to glucose which can be then synthesised into fat for storage, proteins are synthesised from amino acids, and phospholipids are made from glycerol and fatty acids. However there are some organic compounds which despite being essential for a healthy diet cannot be made by cells so must be provided by diet. These are essential amino acids, essential fatty acids and vitamins. Carbohydrates Carbohydrates are a rapid source of energy, they are the body's fuel. The bulk of a balanced diet should be made from carbohydrates. If eaten in an 2004-07-05T22:34:10-04:00 http://75.150.148.189/free-essay/A-Balanced-Diet--25501.aspx Water is essential to life itself, with out water life on earth would not exist. Water is a major component of cells, typically forming between 70 and 95% of the mass of the cell. This means that we are made from approximately 80% water by mass and some soft bodied creatures such as jellyfish are made of up to 96% water. Water also provides an environment for organisms to live in, 75% of the earth is covered in water. Water itself is a simple molecule made up of 2 hydrogen atoms and one oxygen atom, H20. The hydrogen and oxygen atoms are bonded covalently as shown in the diagram of water's electron structure. Water is not a linear molecule, the two hydrogen atoms form a bond with the oxygen at the angle of 104.5o. Diagram of water's electron structure Covalent bonds are formed by sharing electrons in the outer orbits of the quantum shells. In the case of water however the large number of protons in the oxygen nucleus have a stronger attraction for these shared electrons than the comparatively tiny hydrogen nuclei. This pulls the electrons slightly closer to the oxygen nucleus and away from the hydrogen so that the oxygen develops a slight negative charge and the hydrogen's a slight positive charge. This makes the molecules slightly polar. Diagram of water molecule showing slight charges This slight charge means that when water molecules are close together the positively charged hydrogen atoms are attracted to the negatively charged oxygen atoms of another water molecule to form a weak hydrogen bond. The bonds are weak individually but the sheer number of them means that the total force keeping the molecules together is considerable. Diagram of water molecules forming hydrogen bonds Water is an unusual substance, mostly due to it's hydrogen bonds, it's properties allow it to act as a solvent, a reactant, as a molecule with a cohesive properties, as an environment and as a temperature stabiliser. Water can dissolve polar or ionic substances and can keep them in solution because of water's own polar properties. Substances that dissolve in water are know as hydrophilic substances. Ionic substances such as sodium chloride, NaCl, are made up of positive and negative ions. Sodium chloride is held in it's structure by the strong attraction between it's positive sodium ions and negative chloride ions. Normally these ionic attractions require a large amount of energy to break but when put into water the 2004-07-05T21:54:06-04:00 http://75.150.148.189/free-essay/Biological-Importance-of-Water-25452.aspx Ecological Succession Ecosystems undergo changes in their structure and function as time passes. Some of these changes are minor and only affect a small area, others are the cause of major changes in the species present and affect the ecosystem as a whole. Major changes can be caused by changes in climate, external factors such as fire, trampling or pollution and development due to the system itself. Succession is a result of these changes and is defined as a series of progressive changes in an area with one community replacing the other until a climax community is created. A climax community consists of plants and animals, the animals present are dictated by the plants available. There will normally be a dominant species of plant and animal or a number of co-dominant species, these species are normally the most numerous and have the greatest biomass. The climax community is normally seen as the ultimate development of the ecosystem. There are 2 types of succession; primary and secondary. Primary succession is the colonisation of an area which has not supported an ecosystem before, eg sand dunes, volcanoes and new ponds. Secondary succession is ecological succession in an area which has supported an ecosystem whose development to a steady state has been prevented by inhibitory factors such as grazing or fire. When the inhibitory factor is removed secondary succession takes the ecosystem to maturity. The sequence of communities during succession is known as a sere, the type of sere is determined by the environment being colonised, eg a hydrosere is a series of successions in an aquatic environment and a xerosere is a succession beginning in a dry area. The individual communities of each succession are the seral stages, the seral stages are not normally distinct but tend to merge into one another as the succession progresses. During succession energy flow in an ecosystem is fundamentally changed, the changes are demonstrated in the quantity of standing crop in the ecosystem. During early seral stages the energy inputs to the system are larger than the energy outputs, this results in little change in the standing crop. The energy flow is at a maximum during the climax stage. When the ecosystem is disturbed by external factors, eg fire the energy loss is greater than energy inputs. This results in a decrease in the amount of standing crop. The accumulation of energy as biomass is most marked 2004-07-05T09:36:42-04:00 http://75.150.148.189/free-essay/Ecological-Succession-25351.aspx Evolution is defined as genetically based change from generation to generation. IF and ONLY if you look exactly the same as both your parents and they look exactly the same as your grandparents and so on back to the beginning of life (however you define that beginning) can you say that evolution has not occurred. Since I assume you are an organism born on this planet, and that you are a human being, rather than some clonal organism (one that reproduces by budding or similar method), I assume you do not look exactly like both your parents and that they do not look exactly like their parents, and that the differences are, at least in part, genetically based. Therefore, within your own family, evolution has occurred. You have seen evolution. Evolution is a fact, not a theory. How long evolution has occurred, under what circumstances, and what drives it are theories. Evolution is not the theory, HOW life has been shaped by evolution is the theory. When a scientist says "the theory of evolution", it's not the "theory that evolution occurred," it's the "theory of how evolution occurred" that's being spoken of. Even so, a scientific theory is a bit different than "I think the moon is made of green cheese." A scientific theory must be 1) falsifiable and 2) not disproved after some investigation. Falsifiability means that you can disprove it without resorting to supernatural phenomenon. Show me a way to disprove that some god (any god) created the world, that could be done through natural investigation, and I'll say it meets one of the criteria. I haven't seen such a way even offered yet. So far, the theory evolution by means of natural selection (which was Charles Darwin's theory) has been shown to be the best explanation for the path evolution has taken life. The hypotheses ("sub-theories") of the exact nature of how natural selection works are constantly being modified as we learn more and more about our world. Those hypotheses are constantly challenged and should be (that's how science learns more!). And much of what Darwin and Wallace wrote about in their early work has been found to be incorrect, but the basic premise that evolution occurs through natural selection has not been disproved. The theory of natural selection says that organisms which do better in a particular environment will pass that ability to do better on to their offspring, and that those 2004-07-05T04:17:21-04:00 http://75.150.148.189/free-essay/What-is-Evolution--25288.aspx The Theory of Evolution can be divided into two parts, micro-evolution and macro-evolution. Micro-evolution deals with small changes within a species which adapt that species to be better suited to its environment. This process is well supported with scientific evidence and doesn't conflict with a Christian understanding of reality. Macro-evolution claims that through major genetic mutations one species can evolve into another, so over a long period of time fish could evolve into insects, birds and mammals. From this concept it's suggested that all life could have evolved from simple chemical structures, thus life could have resulted from natural processes without the need for a creator. Macro-evolution is highly contentious and its more extreme interpretations challenge conventional Christian thinking. It's sometimes suggested that God chose to create life through evolution, however, there's now a weighty and growing body of both scientific and philosophical evidence that discredits macro-evolution. This article very briefly surveys that evidence. Firstly, there's the question of how life itself originally got started. The theory of macro-evolution suggests how to develop from one species to another, but it can't explain how to jump from no life to life or from unconscious to conscious. There are two questions in this area that macro-evolution can't answer. Firstly, the DNA molecules which store the genetic code for living beings are extremely complex even for the most basic forms of life. Where did the original injection of the genetic information for life come from? The second question centres around an issue termed irreducible complexity. Even in the simplest life forms there are a number of different and complex components which must all be in place for life to occur. Take any of the components away and you no longer have life. The building blocks of living beings are complex and are not independent. How can these components have been assembled separately apart from pre-existent life? A second serious challenge to macro-evolution comes in the forms of fossils. The theory suggests that through genetic mutations over a long period of time, species gradually evolve into new species. If this were the case, you'd expect to find a whole spectrum of species within the fossil record at different stages of evolution. However, the fossil records do not show life evolving from one species to another. On the contrary, there's a notable absence of any fossils of species at intermediate stages of evolution. Further, there aren't obvious intermediate species around today. The 2004-07-05T04:11:05-04:00 http://75.150.148.189/free-essay/What-About-Evolution-A-Christian-Outlook-25286.aspx Imagine thirty or forty years form now. Biotechnology has really advanced. Scientist can now clone people and also change their DNA strands making them better or perfect all around. Do you think that it is safe to tinker with Mother Nature? Is it wise to try and control Mother Nature? Better yet can she ever be controlled? Whether or not she can be controlled is a big of deal. If we can control Mother Nature she will end up controlling us sooner or later. It is not a smart idea to tinker with such a great power that the world has depended on for many years. Scientist can study and try to do many things but one thing they can never do is control Mother Nature. I believe biotechnology is not really necessary in this day in age. What is the point in trying to clone a person and make them better? This technology can be very harmful to us as well as the earth. Biotechnology will change many things and can ruin the balance of nature. In the short story by Jeremy Rifkin, he states "Initial fears focused on the nightmare scenario of newly engineered microorganisms escaping from the lab and causing uncontrollable damage to the other organisms in the environment." (The Ultimate Therapy: Commercial Eugenics on the Eve of the Biotech Century p.542-543) If the balance of nature is interrupted it can cause a lot of destruction. For example if a scientist were to take a species of any type from its original habitat and introduce it to a new environment it will cause the environment to change as well as its balance. The species may eliminate other species causing the food chain to change. Biotechnology is a great danger to the human species. Imagine people walking around looking like twins but one is better in every way then the other. There is already enough racism in this world why do we need to set new standard of a persons well being in his or her society. If scientist were to clone people they could improve the clone, putting the natural human specie at a lower level of life. There would no longer be natural people all the clones would survive caused by Darwin's theory "Survival of the fittest." 2004-07-05T01:02:59-04:00 http://75.150.148.189/free-essay/Tinkering-With-Mother-Nature-25270.aspx The issue of bio-ethics presents a myriad of new dilemmas; all of which have arisen in the recent past, and must be addressed in the near future. The majority of these questions stem from the introduction of new, genetically-engineered organisms. These organisms, or at least many of them, are created in laboratories, by gene splicing, swapping, etc. and essentially, these scientists are playing god, creating biological entities as they want them. This is the main source of the controversy. In more developed countries where genetically engineered disputes may ensue, the trend is total protection through patents and other regulatory and monitoring agencies. These problems come about from identification of the new bio-engineered organisms, and this approach allows the industries and entrepreneurs to recover the enormous costs involved in the research and development of genetic engineering. It promotes the development of products to benefit society, and it allows access for a larger genetic bank for analyses, experimentation, and investigation. There is a second side to this coin-it means that the researchers can assert an excessive price to their 'product' while eliminating any competition for a given period of time. It allows for copies of living things to be made easily and inexpensively. This happens outside the United States, where strict regulations are not in continuity with those pirating compact discs in Japan, bottling Coca Cola in India, etc. No countries spend any monetary amount comparable to the over 300 million dollars to run the patent and trademark office, as the U.S. does. Another observation can be made that because of the time involved and the cost that the free flow of information is inhibited between researchers. These arguments all take place under the umbrella that "Life forces can be controlled by ownership." Many countries take the view that these genetic products are not intellectual property, and as such, not subject to the conventional patent laws. These properties should not be protected and belong to society as much as any organism which has naturally evolved through normal processes. GATT (General Agreement on Trade and Tariff) has attempted to address this issue through a larger commercial / trade package; however, this is a position in which very little agreement among parties is found. In this case, the outcome will most likely be the elimination of the issue in favor of reaching 2004-07-05T01:02:35-04:00 http://75.150.148.189/free-essay/Bio-Ethics--25269.aspx Genetic Engineering: Science vs. Religion What View Does Science Have on Genetic Engineering? For the first time in history, evolution has taken a backseat to the meddling of humankind with their own genetic makeup. There is an "ongoing realization that humanity is capable of directly shaping its own and other species' evolution". As we ease into the twenty-first century, we realize that genetic engineering is undoubtedly going to have a dramatic effect on our lives. It seems that "with genetic engineering, science has moved from exploring the natural world and its mechanisms to redesigning it." Now, we must ask ourselves this, will that influence be for better, or for worse? However, even the responses of science differ in this topic. Scientists remain divided in their opinions. Some have warned against the hazards of genetic engineering, while others have dismissed these perils as inconsequential. Two opposing viewpoints, which is right? Lewis Wolpert, professor of biology as applied to medicine at University College London, says that, "There are no ethical issues because you are not doing any harm to anyone." And indeed, the gist of his statement is staunchly supported by James Watson, a Nobel Prize winner and president of Cold Spring Habour Laboratory. "If we can make better human beings by knowing how to add genes, why shouldn't we do it? The biggest ethical problem is not using our knowledge." They are both extremely critical of excuses that genetic engineering is a bad idea. Are they absolutely right? Are the predictions of "doomsday" just insubstantial bits of fluff with no proof to support these claims? Are we truly so confident as to proceed with no holds barred? Both scientists seem not to have the slightest bit of anxiety regarding potential glitches. They have found a fascinating "playground" in genetic engineering, and appears that it is not only a way for them to earn their livelihood, but also gain fame and fortune. Is their attitude towards this serious issue too cavalier or biased? Are they too unclear about the likelihood of threats to civilization? In contrast, two other prominent scientists have displayed their displeasure about genetic engineering. They have made no secret of the rather strong feelings against genetic engineering. George Wald, Nobel Prize-winning biologist and Harvard professor, wrote: "Recombinant DNA technology [genetic engineering] faces our society with problems unprecedented not only in the history of science, but of life on the Earth. It places in human hands the 2004-07-04T20:54:47-04:00 http://75.150.148.189/free-essay/Genetic-Engineering-Science-vs_-Religion-25259.aspx Skin Cancer Gone are the days when people sent children outside to play to get a little color in their cheeks. They know too much about the dangers of unprotected sun exposure and the threat of skin cancer. Or do they? Despite the fact that 58% of parents remembered hearing about the importance of protecting their children from the sun, children are still playing in the sun without sunscreen or protective clothing (3., p 1). Sunburn is the most preventable risk factor of skin cancer. Skin type and family history cannot be changed. Protection from the sun and education of the potential hazards of the sun need serious attention. The American Cancer Society estimates that over 850,000 cases of skin cancer will occur in the United States during 1996. Of those cases, they predict that 9,430 will end in death (4., p 1). Apparently, Americans still do not have an adequate amount of prevention information to help reduce the disfigurement and mortality from this cancer. Exposure to the ultraviolet radiation from the sun is the most frequently blamed source of skin cancer. Due to the reduction of ozone in the earth's atmosphere, UV radiation is higher today than it was several years ago. Ozone serves as a filter to screen out and reduce the UV light that reaches the earth's surface and its people. Very simply, sunburn and UV light can damage the skin and lead to skin cancer (1., p 1). The American Cancer Society also faulted repeated exposure to x-rays, artificial forms of UV radiation like tanning beds, and contact with chemicals like coal tar and arsenic as other causes of skin cancer (4., p 1). Additionally, if there is a history of skin cancer in the family, an individual may be at a higher risk (1., p 1). Individuals who have experienced only one serious sunburn have increased their risk of skin cancer by as much as 50% (1., p 4). There are three main types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and malignant melanoma. Basal cell carcinoma usually imposes itself on areas of the skin that have been exposed to the sun. It usually appears as a small raised bump with a smooth shiny surface. Another type resembles a scar that is firm to the touch. Although this specific type 2004-06-26T17:48:23-04:00 http://75.150.148.189/free-essay/Skin-Cancer-The-Potential-Hazards-of-Too-Much-Sun-25186.aspx Ruse and Wilson in “Moral Philosophy as Applied Science” give the example of brother-sister incest avoidance as being an ethical code motivated by an epigenetic rule that confers an adaptive advantage on those who avoid intercourse with their siblings. In this discussion, Ruse and Wilson argue that moral laws disallowing incest are redundant relics of mankind’s evolutionary history that provide nothing to mankind but explanations of a hard-wired evolutionary trait (179). I reject this argument. While Ruse and Wilson are undoubtedly correct in believing that mankind’s capacity for moral reasoning is a result of natural selection pressure and that most ancient moral laws have an evolutionary basis, I believe that describing the genesis of moral reasoning in this way provides no information about the content of our moral beliefs now. While our capacity for moral reasoning may have evolved for the purpose of informing our otherwise unjustifiable acts with a sense of objective certitude, it is not hard to imagine that this capacity, once evolved, would be capable of much more than simply rubber stamping mankind’s collective genetic predisposition. In this paper, I will use the example of an evolutionary explanation against intentional killing for personal gain to argue for the existence of a disconnect between evolutionary biology and ethics. Ruse and Wilson might argue that human beings evolved with a genetic predisposition against murder for convenience. It is easy to see how this might be true. A person who kills others for convenience must live apart from society and apart from potential mates or else must be killed by society. This epigenetic rule “predisposes us to think that certain courses of action are right and certain courses of action are wrong (180).” These motivate ethical premises which “are the peculiar products of genetic history” and can “be understood solely as mechanisms that are adaptive for the species that possess them (186).” I reject this notion that evolution completely prescribes ethics. Nature is amoral absent intelligent beings who make moral judgements. Once the capacity for moral reasoning is established, it does not follow that our ethical laws must necessarily mimic our evolutionary predisposition. While in the cases of selection against brother-sister incest avoidance or against murder for convenience it is easy to see how evolution can bring about an outcome that we now judge to be moral, it can just as easily effect traits that we now believe immoral. Few people would 2004-06-13T00:19:11-04:00 http://75.150.148.189/free-essay/Ruse-and-Wilson-on-Incest-Essay-25164.aspx Genetic Testing And Individuals With Disabilities Some individuals within the disabilities community have stated that the use of genetic testing, which results in the abortion of fetuses with certain traits or dispositions, can be interpreted as a form of eugenics. Prenatal screening programs that prevent the occurrence of children being born do exist, as noted earlier in the state of California. "The success of the program is evaluated not in terms of information given to mothers but rather in terms of the number of children with handicaps who were not born. When number of births prevented is the measure of a public health intervention it is hard to say that anything other than negative eugenics fuels support for such programs" (Duster). Whether or not professionals within our society believe that we are moving away from the ideas of the early 20th century of "purifying our society," genetic testing and information is still being utilized for similar eugenics purposes today. We could easily move further away from this idea by providing more information about individuals with disabilities to people within our community, especially prospective parents. Potential parents need more information on raising a child with a disability before they can make an informed decision about genetic testing and diagnosis. Also, genetic professionals must think about their own feelings and points of view on individuals with disabilities if they plan on assisting couples along the way. Genetic testing is not always the case of why people abort the fetus, they have a choice also; in many cases, the prognosis of a disability would not affect their decision one way or another. I believe that if an individual truly feels that they cannot handle the special needs of a child with or without disabilities, then it should be their choice to cease the pregnancy. Many people perceive bearing a child with a disability as a frightful situation, although the truth is that no one, other than the experienced, knows what it is like to bear a child with a disability. Some people that I have spoken with say that it was the most enriching experience of their life, and that they would never change any of their choices concerning the birth of their child with a disability. It may be a difficult situation for a parent to give birth to a child with a genetic 2004-06-10T05:58:42-04:00 http://75.150.148.189/free-essay/Eugenics-Discussinon,-Genetic-Testing-Essay-25129.aspx Sea Otter Research Essay In the oceans today there are many different types of animals. This includes over 27,000 different types of bony fish along with thousands of other types of various animals. But would you have thought that an animal that is part of the weasel family lives in the ocean alongside all these other animals? Well it is true. The sea otter is this animal and has adapted well to an oceanic life. The sea otter has differences between the male and female. As with following with nature the male of the two is the larger animal at approximately four and a half feet in length and weighing in at up to 85 pounds. The female is approximately four feet in length and weighs in at around the 55-pound mark. A newborn young of the species weighs in at 3-5 pounds and is approximately 16 to 22 inches in length. Sea otters do not have the blubber that whales and dolphins do for insulation against the cold. They use fur as their insulation against the cold of the water. The fur that the sea otter has is the thickest fur of any mammal, with up to one million hairs per square inch. Since the fur is the key to the sea otter staying warm the amount of time that the sea otter must groom himself/herself is several hours a day. This is to keep the fur warm and fluffed full of air for insulation. If the sea otter was not to groom for several hours a day the fur would become matted and dirty and lose the insulation properties relied on to keep the sea otter warm. This is one of the reasons that oil spills are so devastating to the sea otter. The oil from the spill mats the animals fur and they die from hypothermia. Another little trick that sea otter's use to conserve heat when resting is to remove their paws and hind flippers up out of the water. These appendages have little or no fur and therefore lose heat very rapidly. However these appendages are very strong and well articulated for use in hunting, eating and swimming. The sea otter employs one more method of keeping warm in the cold ocean temperatures. The animal's body produces a lot of body heat. As the animal is producing a lot of body heat through a high metabolism 2004-06-10T05:55:07-04:00 http://75.150.148.189/free-essay/Sea-Otters-Research-Essay-25128.aspx “To be or not to be…” In the last fifty years new forms of technology have been the center of attention for every human being. It seems that every day scientists come up with some new, perhaps even controversial, and exciting ways to improve the quality of life. These new technologies affect every aspect of life, as we know it. One such technology is the research being done in the area of cloning. Cloning is the production of one or more cells, individual plants, or animals that are genetically identical to another cell, plant or animal. Although the first steps forward in cloning have brought a storm of protest, the experimental research should be studied to prolong the existence of human life. In February 1997, the Roslin Institute in Scotland, a farm animal research facility, announced that it had succeeded in cloning a sheep from an adult cell. The cloned sheep, Dolly, made headlines around that world and launched a fierce debate over the potential uses for this technology. The breakthrough showed for the first time that genetic information encoded in the DNA of an adult cell could be “reset” and made young again. Once reset, the cell with rejuvenated DNA could produce all of the cells needed to grow a complete organism. Since Dolly, much has happened. In the United States, the National Bioethics Advisory Commission issued a report calling for federal legislation to ban human cloning for three to five years because of the moral dangers of cloning. President Clinton imposed a ban on all federally funded cloning research. Other European countries also adopted a similar ban. The misconceptions of cloning have risen from the lack of knowledge about the discoveries. Most people do not understand the basic principles of cloning, and are likely to make rash generalizations about whether cloning is natural or not. Other misconceptions focus on the societal problems resulting from cloning. Many of these misconceptions are only valid in a society without regulations or laws of any kind. People tend to forget that along with new technological developments come rules and guidelines to prevent the nightmarish scenarios that many believe will come true. Each of these misconceptions results from a distortion of the truth. Yet Congress seems hell-bent on stopping the medical advances that cloning can make possible. 2004-06-10T04:18:49-04:00 http://75.150.148.189/free-essay/Cloning-Research-25092.aspx Article Summary – “Criminal Genes” Summary As we all know, genes control much of who we are, but the can they make us criminals? Scientists now believe that there is one gene that is at least partially responsible for criminal behavior. The gene that controls the production of monoamine oxidase A (MAO A) is the enzyme that breaks down excess amounts of certain neurotransmitters. Production of MAO A may be what causes, in part, a higher potential for criminal behavior. In 1972, a study was conducted in New Zealand of 442 subjects. Some of which had history of abuse or criminal tendencies. Researchers found that only 12% of the subjects had low MAO A levels and that 12% represented “half of their generation’s convictions for violent crimes in New Zealand.” The National Center for Scientific Research in France did an experiment with mice. They turned off the gene which controlled MAO A encoding. “The animals exhibited fearless, impulsive behavior.” The mice had the neurotransmitter serotonin levels nine times above normal. In 1993, Harm G. Brunner found in a study of a family of Dutch criminals that they all had a defect in the gene that controls MAO A. This further explains why many criminals have high levels of serotonin. Just having low levels of MAO A does not automatically make someone a criminal. There are plenty of people that have normal lives with low levels of MAO A. The trigger it seems is abuse during childhood. However, abuse does not necessarily mean there will be low levels of MAO A. The combination leads to a very likely chance of criminal tendencies. Scientists speculate that high levels of MAO A may give a higher tolerance for abuse during childhood. “The genotype of high MAO A activity may promote trauma resistance,” says Terrie Moffet, a psychologist who worked on a University of Wisconsin-Madison. Relevancy to Biology Class Although we are not yet to the chapters that cover genetics, we will be covering those chapters shortly I presume. Also, I already have taken the advanced biology course my freshmen year which included a lot of study of genetics. Once we reach the chapter on genetics, which I have skimmed over, we will definitely be covering topics on how the MAO A genotype can affect criminal behavior, most likely along with why it, by itself, does not necessarily make one have criminal tendencies. Reason for Choosing I have a subscription to the 2004-04-30T02:38:24-04:00 http://75.150.148.189/free-essay/Criminality-and-Genetics-Article-Summary-89.aspx