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University Degree: Zoology
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where the complex mitochondria was acquired by endosymbiosis. This allowed protoctists to switch from anaerobic respiration to aerobic respiration, which improved their energy metabolism, increased metabolic flexibility and as the atmospheric oxygen levels increased, defence systems against oxygen toxicity via free radial formation evolved. (see p33, Fig1.27,Ridge,2001) The intracellular bacterium (the symbiont) was assimilated into the larger host cell; the bacterial partner transferred many bacterial genes to the host's nucleus, which resulted in the loss of independence, and new metabolic properties for the host. In most of these interactions, the larger host protoctist takes into its cells a smaller symbiont, instead of being eaten or killed is used whilst alive as a source of new materials or properties.
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These leaf packs are then processed in situ by the stream community. The leaves that enter the stream are nutrient poor as the tree re-absorbs most of the useful sugars and amino acids. When the leaves enter the stream they begin a process called 'conditioning'. At first leaching occurs, over a period of a couple of days most of the remaining nutrients are dissolved out of the leaf. Then fungi and bacteria begin to colonise the leaves and start to break down the lignin and cellulose of which they are made. After a couple of weeks the leaves become soft enough for aquatic invertebrates to begin to feed on them.
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Because feeding a ballooning population is an enormous task, much of the cloning research since and before Dolly has been centered around improving agriculture (Clone, 3). The first and most obvious way in which cloning may benefit agriculture is allowing farmers to replicate their best animals. A farmer can clone the heaviest pig, the cow that produces the most milk, or the chicken which lays the most eggs. This will give farmers the perfect livestock because it will not be necessary to waste food and space on below average animals.
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Comparing the Processes of Osmoregulation and Nitrogenous Excretion Between Insects and Mammals. Due to the unforgiving nature of the natural environment
Another accelerant of 'drying out' is the movement of air. As moisture evaporates off a vapour limited system (e.g. skin of most mammals), the movement of air (less dense) takes away the evaporated water molecules. This in turn allows for more water molecules to evaporate off, leading to 'drying out'. On a membrane limited system (insect cuticle) the outer layer of the animal is waterproof; therefore evaporation under 'normal' conditions does not occur. If these animals were not water permeable then there would also be a limited capacity for oxygen (O2) and carbon dioxide (CO2) to pass through the epithelium.
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Although selective breeding seemed like the ultimate solution, there were many disadvantages to this method, including the selective process of choosing the right male and female animal for the job, the length of time it took the animals to mate (or the many attempts at artificial insemination before a fetus was created), the time it took young to be born and raised, and most importantly, the uncertainty in the expression of valued features in the offspring or the dilution of wanted traits.
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"An ape, a most ill-favoured beast. How like us in all the rest?" (Cicero). How does Great Apes support this view?
Their world is the same as ours, and the chimps make the same assumptions and judgements about us as we do about them; this being that the minor difference between the two species is of overriding importance in how we as a species perceive ourselves. We see from this clever inversion the folly of philosophical enquiry into human existence - it is enquiring into the mere two percent of difference between two extremely closely related species, and ignoring the other ninety eight percent of our shared genetic makeup.
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Ecologism criticises this kind of 'anthropocentric' or 'humanistic' approach to nature. It is the concern for ourselves at the expense of concern for the non-human world that is held to be a basic cause of environmental degradation and potential disaster. They emphasise that the human species is linked to, and deeply dependent upon, other species of plants and animals. All are interdependent participants in the cycle of birth, life, death, decay and rebirth. And all the participants in this cycle depend upon the air and water, the sunlight and soil, without which life is impossible.
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Everyone should spay or neuter their pet dogs and cats. It benefits the pet, the pet owner, the community and even wild bird populations.
One female cat and her offspring can produce 420,000 cats over seven years, and one female dog and her offspring can produce 62,000 dogs over six years, according to The Humane Society's web page. Although altering the family pet alone will not cure this overpopulation problem, it will help to insure that the problem will not get worse. In many areas of the country drastic steps are being taken by communities to control feral cat populations. Many efforts are being made to trap, alter and release (TAR)
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The animal may also consider the possibilities of mate search and aggressive interactions. If an animal can learn the locations and types of patches in an area, a patch can be accepted or rejected before it is encountered, thereby saving valuable search time. However, Smith and Dawkins (1971) found that titmice do not allocate all of their time to the area with the greatest abundance of food (as would be expected), but instead allocated the most time to the best area, and progressively less time to progressively worse areas.
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Universities around the world conduct vigorous research that has led treatments for cancer, penicillin, and many other medicines. However, these benefits have not been seen as advancement by everyone. Activists, such as the group Animal Liberation Front, have become malicious and destructive, even to the point of sabotage. In 1999, the Animal Liberation Front broke into several laboratories at the University of Minnesota and ruined lab equipment, stole lab animals, such as rats, mice, and salamanders, and painted graffiti on the walls of the buildings. Damages were estimated to be over $750,000, including set back of research. The criminals responsible for the atrocity were caught on tape, wearing masks, and pursued by an investigation led by the FBI and local law enforcement (Thomas 1).
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The feathers could only be taken by killing the birds. Due to that, the numbers of grebes fell dramatically. The style for decorating fancy hats with wild-caught feathers was declining before legislation could be put in place to prevent their uses. Across 1860, the great crested grebe was close to extinction in Ireland and Britain. Legislation, changing fashions and raise in the number of lakes available for the breeding resulted with the increase of great crested in Ireland and Britain up to 1000 pairs.
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the Jordan River, continuing into the Jordanian-Syrian plateau. I will shortly mention the subjects of the Kebaran lifestyle A suggestion has been made that the sea-level of today is higher, than at the time of Kebaran. At least very few sites have been found, and one of the largest is even 200 m. below sea-level. The sites are small, about 100 m2, and with very few hearts. Only two sites show the sign of building structures, and they have obviously been settled for longer periods.
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Later still is the development of hepatocellular carcinomas. Foci of altered hepatocytes. Foci are microscopic lesions, distinguishable from healthy liver by various phenotypic characteristics. They are typically located in the periphery or intermediate region of the liver lobule, but may later progress to the centrilobular region . Foci have been observed following the treatment of rats and mice with various carcinogens and hence have been used as markers in the identification of potential carcinogenic substances, . Foci have also occurred in rats following x-irradiation  and in woodchucks infected by the woodchuck hepatitis virus .
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system is not the only thing necessary for the understanding and usage of a language. The manner in which the words are structured is the morphology. Words are than used to make up phrases; the way in which this is done is governed by syntax. In addition a deep knowledge of the meaning and sounds of words, known as semantics, is necessary for the understanding of a language, as is knowledge of the words themselves, the lexicon. Although there is at any given time a finite number of words in any given language there is an infinite number of combinations, or phrases, that can be produced.
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This can have drastic consequences because it affects the ionic potential and thus the rate at which the ions move out of the cell as well. This can cause problems because most tissues require an extracellular fluid high in sodium and chloride and low in potassium. If this is not provided, errors can occur in neural transmission that occurs via a movement of these ions across the plasma membrane of neural cells. The composition of extracellular fluids in vertebrates is used as evidence for their freshwater origin.
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These findings support the expectation that induction of highly cross-reactive HIV-1 primary virus-neutralizing activity by vaccination may be realized." (Quinnan Jr 1) In the grand scheme of things, value must be placed on things in order of importance. Animals are important. There is no questioning that fact. However, I would not rate a lab rat in the same category as a dying grandfather or deathly sick mother. The humans are forever more important. If it comes down to saving my grandfather or a rat, I take my grandfather over the rat every time. I believe everyone would make similar choices.
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source); yeast extract (complex food selection source); 1mM drug (an anti-nematode agent); Basic solution, Acidic solution and Neutral solution; extract of dead Panagrellus nematode worms (to measure the avoidance factors); and secretary products (source of communicating chemicals/pheromones) / Low power microscope / Plastic Pasteur pipettes / Plastic gloves / Forceps and scissors (from dissection kit) / Bottle of distilled water / Sand Grains / Beakers and test-tubes Aim Working in groups of two, and using the materials available, the group of students must design an experiment to address what chemical the nematode senses in the environment.
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The general consensus in the evolution of humankind is that h**o-erectus species were originally from the land of Africa
The second model is the out of Africa or replacement model. This holds that modern humans originated and came from Africa. Through the evolution of h**o-erectus to h**o-sapiens in Africa, the modern humans migrated out to all other parts of the world with some leaving behind to live. These modern human populations took over the regions that they migrated to from the local populations of h**o-erectus which were more or less extinct by that time. Of the two evolution models above, there are reasons probably to favor the replacement model over the multi-regional model.
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Their sole purpose is to entertain. The RSPCA has no power to act. Local vets cannot inspect them. The Police are not allowed to investigate them. In Europe animal circuses are still seen to be a place for enjoyment. The truth in most countries is contrasting to that. There are tortures, pain, and anger exuded here out of the public eye. In the U.K. many councils (the only governing body that allows circuses to perform in the UK by licence) will not allow circuses to perform in their region if they use live-animal acts. Many anti-animal circus groups have formed in order to combat and reveal the mis-treatment of animals.
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The grasslands of North American are called as prairies; they cover about 1.4 million square miles or 15% of the continent.
The frost-free season in prairie averages 100 - 300 days a year. Climate of the eastern part of tall grass zone is gentle, summers are humid and cool, and winters are relatively warm, that is favorable for smooth development of the plants. In the middle and west parts climate is dry and tough, winters are very cold and summers are backing-hot. Besides, drastic changes of daily temperature in this territory of grasslands causes droughts, winds, hails, hurricanes and other natural cataclysms.
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There are two variations of this moth, the light coloured variation known as typica and the dark variation known as carbonaria. In his publication, the Elephant Book, British ecologist H.B.D. Kettlewell states that prior to 1848, dark moths constituted less than 2% of the population. By 1898 however, the number of the dark variation of the moth increased to 95% in Manchester and other highly industrialized areas. The frequency of dark moths in rural area was much. The moth population had changed from being mostly light coloured moths to mostly dark coloured moths.
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But the introduction of trout can not be the real reason for the Yosemite decline because it does not explain the worldwide decline." The reasons listed in the letter seem supportive to the arguer's conclusion that the declination of the number of amphibians around the world suggests the global pollution of water and air. However, a careful examination of this letter would reveal how unfounded it is. The most severe problem with this letter is that the arguer fails to establish a causal relationship between the decrease of the amphibians' number and the global pollution of water and air.
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A much smaller group of organisms are the phylum Cryptophyta (fig 2). These unicellular, flat organisms are only 3-5?m in size and are discussed again later. Protoctista may have no flagella (like Amoeba proteus), one flagella, or be multiflagellates. The Cryptophyta (fig 2) have two flagella with stiff hairs, whilst Giardia lamblia (fig 3), has 8 flagella. Flagella may be used for movement or feeding. In organisms that use flagella for feeding, the flagella are positioned around specialised areas of the cell (a gullet) and push food towards or into this gullet (fig 2.7, Ridge 2001)
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This is fair enough to believe but what if the principle of using animals in research, can be justified by the importance of the findings? According to Coolican (1994, p.485) "comparisons across the phylogenetic scale are invaluable in helping us develop a framework for brain analysis based on evolutionary history". He also states that, "a seemingly useless or mystical piece of the nervous system may serve or have served, a function disclosed only through the discovery of its current function in another species".
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An interesting parallel in terms of vocalizing actions is found in birds. The bird song is verbal and functional; part learned and part generic, (similar to humans) marks territory and courts a mate. There are also regional dialects in bird song proving it is not all generic. If we consider language synonymous with speech, and speech an essential form of communication then we will inevitably conclude that animal communication methods are basic and in some cases non existent. However, while human communication is largely verbal, animals tend to communicate through displays.
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