2007-09-28 16:15:55 · 9 answers · asked by Marica F 1 in Science & Mathematics ➔ Biology
There are two reasons.
First, DNA isn't just the repository of genetic information for the individual (the entire organism). In other words it isn't just needed at the time of reproduction of the individual.
The *main* job of DNA is as the repository of information for basic *cell* operation. This is both the information that allows every cell to live (metabolism, production of energy, removal of waste, etc.), and the information that each cell needs to serve the function in serves for the body. For example, the cells in your pancreas could not manufacture insulin for you if each pancreatic cell did not have the instructions for how to manufacture an insulin molecule.
Second, DNA is needed to produce new cells ... which is a constant process not just during development from fertilized egg through embryo to youngster to adult ... but also on a daily basis, cells are constantly being replaced. If the DNA was all in one repository, then (for example) if you cut yourself, the instructions for manufacturing new skin cells would only be in that central repository ... so skin cells would have to be manufactured there, and then move somehow to the point of injury. That would just be too major a redesign of how bodies grow and repair.
In summary, evolution cannot move in a direction that violates basic principles of how life works.
2007-09-28 23:44:41 · answer #1 · answered by secretsauce 7 · 1⤊ 0⤋
Multi-ceullar organisms were believed to have come from uni-ceullar organisms that "stuck" together and developed a positive symbiotic relationship with one another. Each cell, had it's own DNA to contribute.
Fast forward to now. Imagine having only one area of the body (or more extremely, one cell) that had all the DNA in it. Your whole body would have to depend on that part of the body to make the proteins necessary for the rest of it. If that part of the body should be at risk, you would be screwed. Also, remember that every cell in your body for every tissue and organ you have has the exact same DNA, but the advantage of having the same DNA in it is that different parts of the body can turn on and off certain genes and this is what allows different parts of the body to produce different products and thus organs/tissues can provide different functions. Also, DNA can mutate due to certain harmful exposure to the environment. Imagine if you had only one copy of DNA or one with copies of DNA that happens to be exposed to mutagenic stuff, you would be really screwed.
2007-09-28 16:47:06 · answer #2 · answered by CNTB 3 · 0⤊ 0⤋
secretsauce gave a great answer and that i'm in basic terms including one ingredient. Our DNA isn't indestructible. in case you had in basic terms one critical repository of DNA and something got here approximately to the DNA that broken it previous restoration, or gets repaired incorrectly (which occurs each and every of the time) you would be caught devoid of any good copies of DNA.
2016-12-28 06:48:06 · answer #3 · answered by sallas 3 · 0⤊ 0⤋
DNA is in every living cell. If it was in a single "repository" you would have no other living cells Kinda hard to evolve that way:)
2007-09-28 16:20:41 · answer #4 · answered by impstout2 4 · 0⤊ 0⤋
DNA in every cell allows for changes and "mess ups" without these mess-ups...organisms will never go through evolution. The cells in multiorganisms need to be able to differentiate. The liver cell has a large percentage of similarity to your skin cell, but they are evoluved to operate specifically in the liver. A single database of DNA would not allow for change...even if it can change...then the organism will die at the first sight of change in the environment.
2007-09-28 16:45:21 · answer #5 · answered by blackeagle 2 · 0⤊ 1⤋
The job of the DNA is to run the cell that it is found in. Having DNA in one central location would be very inefficient.
2007-09-28 16:18:45 · answer #6 · answered by ecolink 7 · 2⤊ 0⤋
the genes on the DNA encode proteins the cell needs. it's not very efficient to have everything made in one place and shipped around to different parts of the body... better to make them on site.
2007-09-28 19:49:52 · answer #7 · answered by Anonymous · 2⤊ 0⤋
You are looking at replication from the position of the organism. Look at replication from the genes viewpoint. The genes " job " is to replicate copies of itself. We arr the vehicle that provides the genes the opportunity to do just that; so they do it in spades.
2007-09-28 16:29:10 · answer #8 · answered by Anonymous · 2⤊ 0⤋
We were created in God's image, so ask him....
2007-09-28 16:19:35 · answer #9 · answered by Scotty J 3 · 0⤊ 4⤋