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GCSE: Variation and Inheritance

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  1. Human evolution is a theory that states that humans evolved from primates millions of years ago, evolution in humans has been happening for about eight million years and helped shaped what we look like today.

    Climate change has a huge effect on the physical evolution of our ancestors, when the environment changed it forced our earliest ancestors to start living on the ground because of the degrading of their habitat. Old ocean fossil records from the Great Rift Valley located in East Africa show that the area was changing to drier conditions. About 2.7 to 1 million years ago there were unusual wet and dry periods, this may have caused early hominids populations to adapt and readapt to the fast changing environment.

    • Word count: 1480
  2. Huntington's disease is a hereditary neurological disorder of the central nervous system

    Difficulties with speaking and swallowing * Weight loss * Seizures * Depression * Anxiety Causes & Risks Huntington's disease is caused by a single defective gene on chromosome 4. This leads to damage of the nerve cells in areas of the brain including the cerebral cortex.

    • Word count: 371
  3. What are the main theories of how and what killed the dinosaurs?

    Though it was hunted the main reason for its extinction was pollution of its wetland habitat. But obviously because modern day humans were not around when the dinosaurs died we did not cause the mass extinction 65 million years ago; the cause must have occurred naturally. What are the main theories of how and what killed the dinosaurs? There are two main theories of what natural changes in the environment that could have caused mass extinction 65 million years ago, killing dinosaurs that had been roaming the world for over 150 million years.

    • Word count: 899
  4. Genetically engineered food, also known as Genetically Modified or GM food, is food that has been altered at the genetic level to produce a better tasting, longer lasting, or more resistant product.

    They are also cited as more economical, despite the initial higher cost of the seeds. The rationale is that they reduce the need for pesticides and herbicides as well as reducing the manpower needed to successfully grow the crops, which should translate into improved financial gains.Improved food quality is another benefit associated with GM foods. A tomato, for instance, can be engineered to stay fresher for longer, thereby extending its shelf life in the supermarket. Yet another benefit that is believed to occur from GM technology is that crops can be engineered to withstand weather fluctuations and extremes.

    • Word count: 829
  5. Should We Trust Monsanto? Controlling Our Food: The World According to Monsanto is a documentary which investigates the company by compiling pieces of its history,

    A genetically modified organism (GMO) is the result of altering the genetic material of an organism using genetic engineering. Controlling Our Food: The World According to Monsanto is a documentary which investigates the company by compiling pieces of its history, revealing unpublished documents and first-hand accounts. The film was premiered in France on the 11 March 2008. Controlling Our Food: The World According to Monsanto is going to be the subject for my case study and I will be trying to respond to the following question: 'Should We Trust Monsanto?'.

    • Word count: 770
  6. What killed the dinosaurs? Im going to write about two different theories that could explain what killed the dinosaurs.

    The earth was full of vegetation so finding food was not a problem. Whether carnivore or herbivore all the animals were linked into food chains and webs an example of a food web is shown in the picture. The chain shows that if the plants get damaged then the dinosaurs wouldn't have anything to eat and die because insects eat plants, then lizards eat insects and then the dinosaurs eat the lizards and survive. The KT boundary Rocks change over time and form layers over time which can be dated. The KT boundary is a layer of rock that is dated to 65 million years ago which is shown in the picture below.

    • Word count: 1022
  7. Cystic fibroses

    The sweat glands and the reproductive system are also affected. Cystic fibroses is an inherited disease of the body's music and sweat glands. Cystic Fibrosis does not go away and it gradually gets worse over time. Cystic Fibrosis is usually deadly, on average, people which Cystic Fibrosis live about 3o years. Our bodies depend on special cells that hide mucus and sweat in order to function normally. Our lungs have these special cells in them. They mucus the special cells which is watery and helps trap dirt and expel it to the outside.

    • Word count: 717
  8. Free essay

    Genetically Modified Foods Report

    But on the other hand genetically engineering the plant is much more efficient and less time consuming. Genetically engineering a plant is where the manipulation of an organism's genetic endowment by introducing or eliminating specific genes through modern molecular biology techniques. Genetically modified foods are useful to humanity because they are making food easier to grow and keep longer. They are making our lives easier because if the plants can grow in drought areas that means they can grow them without much water and more for us.

    • Word count: 860
  9. Gene Technology

    The organism which will now have the new gene in their DNA is called transgenic. This technique can be very useful, an example of how is insulin. Insulin is a hormone released by the pancreas to control blood sugar levels and when it enters the liver, converts the excess soluble glucose to an insoluble form called glycogen, it is then stored in the liver and muscles. When a person does not produce enough or any insulin they suffer from a condition called diabetes. They then must inject themselves with the hormone to prevent their blood sugar levels from getting to high.

    • Word count: 908
  10. This case study is about human clowning and should it banned or not. It will provide information about human cloning advantages and disadvantages will be included.

    Reproductive cloning has not been performed and is illegal in many countries. A third type of cloning called replacement cloning is a theoretical possibility, and would be a combination of therapeutic and reproductive cloning. Replacement cloning would mean replacing extensively damaged cells or other damaged body parts. Quote:"Therapeutic cloning will in time allow scientists to create organs that are a perfect match for those in need of a transplant. The cloned organ would be based on the recipient's genetic material and would not require the use of debilitating immunosuppressive therapies. There would also be no chance of rejection, which is fatal.

    • Word count: 860
  11. Charles Darwin: The Origin Of Species

    with large effects (such as hornlessness in cattle) wanted to make mutation responsible for positive evolutionary change and so only believed in natural selection to get rid of negative and harmful variants" (Darwin, C. 2003. the Origin of Species. United States: Penguin Group). Meaning that the Lamarkians believed that species lost parts of them that they didn't need, the Vitalists believed that species were created separately whilst Darwin clearly states "that species had not been independently created, but had descended, like varieties, from other species" (Darwin, C. 2003.

    • Word count: 993
  12. Should Biological Warfare Research Continue?

    Biological warfare is the use of any pathogen (bacterium, virus or other disease-causing organism) as a weapon of war. A biological weapon may be used to kill, seriously harm someone or something, or disable them in different ways. Biological warfare is technically a military technique usually used by nation-states or non-national group, such as a terrorist organisation. It has been practiced excessively throughout history. Before the 20th Century, the use of biological agents took three major forms: - Deliberate poisoning of food and water with infectious materials - Use of microorganisms, toxins or animals, living or dead, in a weapon system - Use of biological inoculated fabrics, meaning introducing a micro-organism into something.

    • Word count: 2488
  13. Stem Cell Research

    3 3 Adult Stem Cells We have known about adult stem cells for 30 years 4. The great thing about adult stem cells is that we can remove them from living human without harming them. Adult stem cells can be found in: the brain, bone marrow, skin, fat. Scientists don't however; believe they have the same potential as embryonic stem cells - the ones found in the early stages of an embryo. In Melbourne, Australia, researchers have found a method which may possibly help in retrieving adult stem cells from the human brain. This is believed to be able to cure diseases such as Parkinson's disease or other neurological conditions4.

    • Word count: 2090
  14. The Ethics of Genetic Engineering

    However, this success was in some ways regarded as a failure; dolly was the only success of 245 attempts. Another field of genetic engineering is that of genetically modifying crops and plants. Critics say that GM crops are unethical because the crops threaten the environment. Genetically engineered crops may devastate the environment. Triple herbicide resistant weeds have already mutated, making it necessary to use abnormally strong weed killers.4 Crops provided with bacterial genes that allow them to make their own pesticides, for example, may result in the death of harmless insects. This has the potential to escalate on a large scale, affecting a fine balanced food chain.

    • Word count: 1024
  15. Genetics Research

    Chromosomes- Pieces of Chromatin wraped around each other, they are organized. Chromatin- mass of unorganized genetic material. It contains the chromosomes that duplicated, but aren't visible yet. Like in Interphase. They are made up of protein spools. Protein Spools-Genes and protein wraps around itself and folds. Classified as: primary, secondary, tertiary, quaternary. The higher the number the more folds it has. Gene- Long segment of DNA. Sister Chromatids- Two identical copies of a single chromosome that are connected by a centromere. Biotechnology- Crossbreeding, and Genetic Engineering-Altering the information contecnt of DNA through use of recombinant DNA technology.

    • Word count: 4625
  16. Creationism/Evolution essay

    Darwin's work soon led to overwhelming acceptance of Evolution within the scientific community. In the 1930s, Darwinian natural selection was combined with Mendelian inheritance to form the modern Evolutionary amalgamation, in which the connection between the units of Evolution (genes) and the mechanism of Evolution (natural selection) was made. This powerful theory has become the main organizing principle of modern biology, providing a unifying explanation for the variety of life on Earth. Evolution is believable because there is proof of it taking place. 80 years ago, rats could be successfully contained using the poison Warfarin, which stopped the rat's blood from clotting.

    • Word count: 714
  17. Analysis of Charles Darwin's Origin of the 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.

    • Word count: 2172
  18. Motor Neurone Disease Information Brochure

    A mutation is an error in the genetic code which causes a gene to work abnormally. This gene is called the superoxide dismutase 1 gene (SOD1) and is located on chromosome 21. About 15% of familial MND is caused by mutations in the SOD1 gene. People who inherit a faulty SOD1 gene have a high, but as yet uncertain, chance of developing MND in later life. However, some people with a mutation in their SOD1 gene will not develop MND during their lifetime. Some people who appear to have sporadic MND also have mutations in the SOD1 gene.

    • Word count: 803
  19. Genetic engineering: techniques, benefits and risks

    Common techniques used in genetic engineering Recombinant DNA Uses plasmids and viruses to insert foreign genes into cells an example of this is bacteria being given the human insulin gene so that when the bacteria multiplies it creates insulin. This means that diabetes can be treated better then before and many people have been saved from diabetes thanks to genetic engineering. Viruses can also be used as a vector by adding a new gene to the genetic material of the virus.

    • Word count: 678
  20. Is cloning the way of the future

    Cloning Cloning is when organisms are genetically identical to another. Cloning is the creation of cells or a whole animals using DNA from a single parent by passing the normal reproductive process. The clone has identical DNA to the parent. (Picture taken from BBC BITE SIZE) Natural cloning Cloning is when an organism is genetically identical to one another, however is it unnatural? Well cloning has been done for many years, by plants and other animals, Natural has being cloning for nearly over a billon years, which, has just recently been acknowledged.

    • Word count: 2496
  21. Human cloning - should it be banned?

    can reproduce asexually. * Asexual reproduction is a type of reproduction which does not involve meiosis, or fertilization. It is a form of mitosis. * Asexual reproduction only takes one 'parent' cell. * This is done when single celled organisms, such as bacteria, grow and then divided into two 'daughter cells'. * All offspring produced asexually are clones: so are therefore genetically identical to the 'parent' cells, which in this case are plants. Asexual reproduction Commercial cloning of plants: * Clones are genetically, and physically, identical to the 'parent' plant. * [so] If a particular breed or colour of plant is desired, it is much easier to make sure that that colour or breed is produced by asexually breeding it.

    • Word count: 1148
  22. Genetically modified foods and farming

    of Flora and Fauna All of the above points need to be ore commonly practised but for this to happen more financial support to keep to the environmental farming systems is needed. Organic farming emphasises environmental protection and animal welfare. The ACOF looks after the organic farming that happens in the UK. Their job is to exclude synthetic fertilisers, pesticides and growth regulators. They rely on crop rotation as some of the chemicals kill insects and birds but lots of the organic farmers are hoping for new equipment to help them farm.

    • Word count: 1158
  23. Organisms Sexual and Asexual

    The aphids may go on reproducing gamogenetically (asexually) without cessation for many years. Likewise, in warm and tropical areas or during the growing season, aphids reproduce asexually without interruption. Daphnia The freshwater crustacean Daphnia reproduces by parthenogenesis in the spring to rapidly populate ponds, then switches to sexual reproduction as the intensity of competition and predation increases. Queen Bee An example of non-viable parthenogenesis is common among domesticated honey bees. The queen bee is the only fertile female in the hive; if she dies without the possibility for a viable replacement queen, it is not uncommon for the worker bees to lay eggs.

    • Word count: 675
  24. The impact of Genetically Modified Foods

    However, Europe has yet to use the products commercially in large amounts with Spain and Germany producing less than 0.002 % of the amount of GM crops of the USA alone that are producing over 117.6 million acres of GM crops for the world market2. Before looking into the use of GM products in more detail, my own views on the use of GM technology in the production of foods are that there is little known about the future effects of using them.

    • Word count: 1441
  25. In today's society, genetically modified food is a widely discussed topic with many controversies and benefits. Genetic modification is used in many different techniques to control a variety of traits of plants

    The FDA, the USDA, and the Environment Protection Agency (EPA) regulate food in the United States. The FDA has a better reputation of being trusted by consumers, because most consumers are not educated in the fields of science and technology. Most Consumers feel inadequate to make important decisions about complex issues that affect the world as a whole. Although science is the major source of the GM food debate; economic, political, environmental, and socio-cultural issues are also a part of the mix. Since 1995, food and agricultural issues have been under the preview of the WTO, whose meetings have drawn protests-sometimes over food and agricultural issues.

    • Word count: 580

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