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[Photo Galleries ][Polls Discussion ] Posted by Simon Roughneen on November 14, 2003 at 11:37:57: In Reply to: Re: What is DNA? posted by G on November 11, 2003 at 14:15:14: But seriously...(sorry to be boring) Every organism has different sequences of these "letters" (A, T, G, C), and hence different genes. Most organisms have some genes in common e.g. all primates have specific genes that tell us how to be primates. The more closely related two organims are, the smaller the diferences in their DNA sequences. For example, there is something like a 98% similarity between humans and chimpanzees. BUT the definition of a species is: "two organisms are said to be the same species if they can breed to produce an offspring that can itself prduce more offspring". If you took half of an ape's DNA, and half of a human's DNA (to put it very simply) and combined them into a single cell, it is very unlikely that the genes would all work together in such a way that that cell could grow, divide, and then develop into a full-functioning organisms. For a start, organisms rely on DNA being held together in two strands, and the way these strands are held together is very dependent on the sequence of the bases (A, G, T, C) in the strands. There would not be nough similarity in the DNA strands from monkeys (or other apes) and humans to allow the strands to be held together propery, so the cell could not divide and develop into a "monnkey-man"
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