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| DNA Forum Discuss DNA, the molecule of hereditary. Topics include DNA structure, DNA replication, DNA function. |
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| DNA copies itself every time a cell goes through the cell cycle and mitosis- growth or repair and replacement of cells we lose constantly such as skin or digestive system epithelium. There are errors, but enzymes such as DNA polymerase catch and correct many of them. |
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| Yes, there are possibiliies of DNA mutations when DNA replicates, but it's rare. If DNA didnt replicate, youd be dead. You have to have a DNA strand for each new cell you have in your body and eventually cells in your body are going to die. |
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| DNA reproduces all out lives, yes. Evolution doesn't happen on errors because it will only affect the cells that change and multiply, the rest of the body will keep the original code. Evolution might occur if sperm or eggs are mutated but then you have to wait for the next generation. Errors are generally harmful leading to the ageing process as the telomeres wear out and sometimes cancer. |
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| Yes, DNA reproduces, but the reproducing "machine" called DNA polymerase has several proof-reading and editing functions in it so the mutation rate in it is very small (I can't remember the exact number, but it is like 1 in every million or 10 million base pairs...an average DNA strand is 3 billion bases pairs in length). Also, most mutations in human DNA really doesn't affect anything. A lot of human DNA, monkeys, pigs...anything not a single cell (bacteria, etc.)...is filled with what is called "junk DNA" so mutations here doesn't affect your genes (which is what really defines who you are). Plus, DNA has another "safeguard" against mutations called a "degeneracy code". This is where a mutation in a gene doesn't do anything to you b/c the it still codes for the same thing. Does it happen, yes, does it affect you during the course of your lifetime...no, since your body is comprised of billions of cells containing DNA... Mitochondrial DNA is the exception to the rule...it has a high mutation rate (due to either a lack of proofreading or limited proofreading...I can't remember which), but once again since you have billions of cells, the "good" ones over compensate over the bad ones and of course not all mutation are bad/good...most times they mean nothing. |
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