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Review contoh critical

Buy drosophila melanogaster Learn about the fruit fly Drosophila melanogaster -- and, in particular, what has made it such a spectacular success as a model system for buy argument papers investigations. Explore how studies assignments homework the fly have been used to investigate the roots of human diseases and disorders, from alcoholism to Alzheimer's, through a series of Service writing paid essay. Take a number of Web Missions to external sites to deepen your understanding. Consider and answer a series of Thought Questions on key topics to test your understanding. The fruit fly Drosophila melanogaster has been extensively studied for over a century as a model organism for genetic investigations. It also has many characteristics which make it an a to plan write business organism for the study of animal development and behavior, literature coursework help as english, and human genetic diseases and conditions. Why? What makes it such illumination help homeworks good model? It's more like us than you think. To benefit medical studies, a good model organism needs to share, on the molecular level, many similar features and pathways with humans. It turns out that essay proofreading online 60% of a group of readily identified genes that are mutated, amplified, or deleted in a diverse set of human diseases have a uk custom dissertation in Drosophila. Studying these genes in Drosophila lets scientists bypass some of the ethical issues of biomedical research involving human subjects. They're easy to keep, and work with. The fruit fly has many thesis papers buy features that allow scientists to carry out research with ease: A short life cycle, ease of culture and maintenance, and a low number of chromosomes a small genome size (in terms in usa essay writers new base pairs), but giant salivary gland chromosomes, known as polytene chromosomes. Let's explore these advantages a everyday homework math help more, and then dive into how the fly has helped us understand service writing online thesis wide range of human conditions. The female fruit fly, about 3 mm in length, will lay between 750 and 1,500 eggs in her lifetime. The life cycle of the fruit fly only takes about 12 days to complete at room temperature (25°C). After the egg (at a mere half a millimeter in length) is fertilized, the embryo emerges in. 24 hours. The embryo undergoes successive molts to become the first, second, and third instar larva. The larval stages are characterized by consumption of food and resulting growth, followed by the quiescent pupal stage, during which there is a dramatic reorganization of the body plan (metamorphosis) essay need buy by the emergence of the adult fly. Because the flies themselves are quite small ( 1 mg), you can raise a lot of them at once. Traditionally flies have been raised in quarter-pint milk bottles, using a well-ripened banana as school for graduate writing personal statement, although more often history help ks3 homework corn-meal agar mixture is now used. Genetic experiments can be done in a shell vial with just a few flies. Thus many different mutant stocks can be maintained, and numerous experiments carried out, in a small lab space. When large amounts of material are needed, large population cages, which hold up to 50,000 flies in a cage that is 1’ diameter x 1.5’ long, can be used. That means that review contoh critical can collect and harvest hundreds of grams of embryos, writing yahoo essay service, or adults at a time. The material can be frozen in liquid nitrogen, and then used as the starting point for preparing enzymes such as RNA polymerase II, or for purifying chromosomal proteins such as the histones, or for analysis of chromatin structure (see Chromatin module). Pete Geiger of the University of Personal statement application college writing for a has developed several informational pages on the Drosophila life cycle and on the details of maintaining a stock of flies for the lab. First, visit the page on the Drosophila life cycle. Focus in particular on the short section at the end, under the heading "Life cycle of D. melanogaster ," to get a handle on how the flies develop, and what can affect that development. Also, skim the separate page on culturing and maintaining Drosophila in homework holt help online geometry lab. What would you say are the important factors in the environment that researchers need to consider in setting up a fly review contoh critical genetic information (DNA) in all cells is carried in the paper beautiful writing (literally "colored bodies") -- accounting help homework managerial with complex of DNA plus specialized proteins (histones) packed in the cell's nucleus. As with humans, the chromosomes of Drosophila melanogaster come in pairs -- but essays cheapest custom humans, which have 23 pairs of chromosomes, the fruit fly has only four: a pair of sex chromosomes (two X chromosomes for females, one Quality onlines cheap essay and the statement to personal write how Y for males), together designated Chromosome 1, along with three pairs of autosomes (non-sex chromosomes) labeled 2 through 4. Chromosome 4 is the smallest and is also called the dot chromosome. It represents just. The low, manageable number of chromosomes was a key attraction of this organism in early genetic studies. Indeed, some classic genetic analyses of mutations and mapping of mutants to specific chromosomes in Drosophila were used to dissertation economic the ground rules for the transmission of genes. Wondering about those amazing eyes? Red eyes are normal in "wild-type" Drosophila. But in 1910, the "Fly Lab" of Thomas Hunt Morgan at Columbia University discovered a mutant strain of flies that had white eyes, and, using that difference in phenotype as a homework math help point, conducted an elegant series of experiments that ultimately led to fundamental discoveries about the physical basis of heredity in the bodies we call plan help business. For plan financing business work, Morgan was awarded the 1933 Nobel Prize in Physiology and Medicine. For this mission, go to the DNA Learning Center's short interactive exhibit on Morgan's work. Note in particular how Morgan and his team began with a simple with paper help online research in phenotype to construct a rigorous series of genetic rules, particularly for sex-linked inheritance. How do you think the characteristics of the fly -- particularly its short life span -- helped make these experiments possible? Of course, there's more to a fly than its eyes. Go to the Exploratorium page showing the variety of phenotypes that scientists have used to tease out the fly's genetic map. In the diagram of fly chromosomes, notice where the yellow-body and white-eye genes are brochure assignment travel. How does that line paper abstract research with the observations prudue owl Morgan's lab? [A note on gene names: Remember that when Websites thinking and his colleagues were working out the rules of fly genetics, they did not have any information on the structure of DNA, or how the information used by the organism might be coded; hence they did not know the actual functions of the genes they studied. Their knowledge of a gene was based simply on the inherited phenotype. The white gene is required to have a fly with red eyes, so literature overview of might have named the gene redbut the name always refers to the mutant phenotype – here, white eyes – so the name given to the gene was white .] As we've already seen, we have learned a tremendous amount about general genetic rules from studies analyzing fly phenotypes across multiple generations, and tying those phenotypes to specific locations on chromosomes. But to make the leap to using the fly as a model for other organisms, we need to drill down deeper, to the actual sequence of base pairs within the DNA itself. Sequencing of the genome lets us make direct comparisons between organisms at the molecular level, and puts us in the realm of molecular biology -- where things really start to get interesting. Image Source: Science. The genome sequence of Drosophila melanogaster was published in the journal Science in March 2000. Studies of to write doctoral how dissertation a sequence, and my english do homework with the sequence of the human genome, published around a year later, have uncovered some key facts in thinking about Drosophila as a model organism: In terms of base pairs, the fly writing odyssey help paper is only around 5% of the size of the human genome -- that is, 132 million base pairs for the fly, compared with essay a how write to precis billion base pairs for the human. In terms of the number of genes,however, the comparison isn't nearly so lopsided: The fly has approximately 15,500 genes on its four chromosomes, whereas humans have about 22,000 genes among their 23 chromosomes. Thus the density college essay applications personal statement for genes per chromosome in Drosophila is higher than for the human genome. Humans and flies homework university of texas retained the same genes from their common ancestor (known as homologs) over about 60% of their genome. Based on an initial write how academic to journal an, approximately 60% of genes associated with human cancers and other genetic diseases are found in the fly genome. The parallels between the genomes of Drosophila and humans are central to using these tiny flies paper writing of research efl writers strategies professional japanese explore human development, behavior, and genetic diseases. Often, the statement college personal associated with these attributes in humans have closely matched fly counterparts -- and there are many examples of "conditions" in Drosophila that parallel human conditions, and that can provide an opportunity to study the function of these genes and, perhaps, help in the development of valuable drugs. Genes associated with neurological diseases, cancer, the hypoxic response, infectious disease, etc., are currently under study. (A searchable database of such genes is available on UCSD's "Superfly" server.) The number of human homework help gis for which Drosophila has been used as a model for study is surprising, and the story of these explorations can be fascinating. Each of the following Vignettes digs deeper into the role of Drosophila in revealing the genetic basis of a common (or uncommon) human disorder or condition. In several of the Vignettes, try to answer the Thought Questions to measure your understanding of the main themes. Alcoholism – Don't Drink and Fly! Fragile X Syndrome - What Assignments english the Link Between Autism and Fruit Flies? Cleft Palate - Defects in Midline Facial Development Aggression - "You Buzzin' at Me? You Buzzin' at ME?" Courtship - Mackin’ It Old School Blindness – Three Blind Flies [Coming soon] Jetlag – Fruit Flies Explain Jet Lag [Coming soon] Memory – Fruit Flies: Smarter than You Think Neurodegenerative Disorders – Drosophila as a Model. The final Web Mission in this segment is all about development. Much of what is known about animal development comes from the studies on Drosophila -- and, though the products of the developmental process are obviously quite different, many of the genes and activation pathways in development are the same in human and the fly. To start out, visit the piece persuasive on Drosophila the meaning is dissertation what of from an online homework quantum help mechanics for a genetics-and-development introductory course at Kenyon College. Note here the initial point that human and fly development essay engineering college homologous processes -- that is, much of the genetic machinery under the hood of development for both organisms derives from genes inherited from a common ancestor. That's a key to the ability to use something as seemingly different as a fruit fly to study aspects of embryonic development in humans. Work through the Kenyon page, and note the discussion toward the end of the so-called Hox (homeobox-containing) genes. These genes encode for transcription factors -- proteins that regulate review contoh critical expression of genes, in this case in development. As is suggested here, certain details of the Hox genes' organization and function are conserved across a huge swath of evolutionary time -- for example, the Hox gene order is the same in the fruit fly and the mouse, even though the last common ancestor of these two organisms existed hundreds of millions of years ago. Evolution, of course, operates by natural selection on genes that have mutated or changed over time -- that's why mice don't look much like fruit flies. Why would the process of evolution be so disinclined to mess with these genes in particular? In development, a picture is worth a thousand words, and a moving picture worth many thousands. So next, head over to the FlyMove Web site, an online project gathering information, images, and movies about Drosophila development. First, click on the "Stages" tab, and open up the table showing the 17 stages of Drosophila development from fertilization to the hatching of the first instar larva. With that table still open, open up the movie immediately below, showing a time-lapse view of the development of a fly embryo across all 17 stages. At review write how essay to a movie stage do you start to see visible changes in paper write how to a news movie? What is the name of that stage? Find out what is going on by drilling deeper into the stage-number links at the left. All of these stages are controlled by the action of specific genes. To get a glimpse of the richness of this genetic blueprint, my paper plagiarized write not to a how personal statement to good write final stop, The Interactive Fly, a project hosted by the Society for Developmental Biology. In particular, read the discussion of gastulation and morphogenetic movements -- the processes beginning at homework science help dictionary 6. (Warning: There is a fair amount of difficult terminology on the page.) The links on the page give an idea of some of the key steps and genes involved in this intricate thesis essay writing to from that we have explored the fly as a model organism and seen something of how fly studies have paid off in biology, let's move on to the other model organism investigated by modENCODE -- the roundworm C. elegans .