Wednesday, February 29, 2012

How might alterations in DNA structure be harmful to a species?

How might alterations in DNA structure be harmful to a species? How might such alterations be beneficial? What type of genetic change is most important for evolution?How might alterations in DNA structure be harmful to a species?
Mutation is most important for evolution, as it provides the genetic variation that make recombination, random drift, (and eventually natural selection itself) possible.



The most basic type of alteration to the structure of DNA comes in the form of a mutation. Mutations can be both harmful and beneficial, depending on the outcome. It all depends on whether the mutation causes a favorable genotypic and/or phenotypic result.How might alterations in DNA structure be harmful to a species?
An analogy that might be helpful is comparing the process of DNA making proteins as a song. A song has certain notes that must played at certain times. There are pauses (exons) and notes (introns) that must be played at certain moments for the song to "make sense". If there is too long of a pause (mutations causing a reading frame shift) then the song does not make sense.



Point mutations are usually so insignificant that they do not alter the "notes being played." But if there's too many mutations called deleterious mutations, the note (intron) will not translate into an understandable sound. So it just sounds like noise.



There are some time specific external (environmental) changes that cause mutations which may help a species adapt to its environment. Which would be called a beneficial adaptation. A harmful mutation is a mutation that affects either the sexual reproduction of a species or affects its survival rate.



What type of change is most important for evolution? Change is really an objective measuring stick. Going back to the analogy of the song, if you miss a note or pause too quickly or for too long, the song itself changes. But if the song is an "improvisation" of sorts, then it will "sound good" because of the environment its in.



Phew, Now you owe me a penny for my penny thoughts.



I hope this helped...

later.How might alterations in DNA structure be harmful to a species?
Alteration of DNA can lead to problems such as improper base pairing. Improper base structures tell DNA POL that it's a different base, for example for example through deamination loss of amino groups from the base the A looks like a Hypoxanthine which looks like a G, C without the amino group looks like a Uracil which is similar to Thymine in the case of DNA obviously base pairing with Adenine, instead of an Adenine you place a Guanine now instead of making A=T YOU are forming G= C which can lead to improper protein synthesis, Alterations in the DNA can be beneficial to Viruses and certain microrganisms. Viruses grow drug resistance because they have changes, alterations in their DNA sequence/ structure which can lead to different proteins being formed which causes drug resistance and in some cases multi drug resistance, the drugs that used to block a certain protein can no longer block them since the entire protein has been changed. Often the genetic change is inferred from phenotypic changes that are heritable

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