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21_l

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    >> So are there any other ways that a mutation can be introduced?
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    >> Actually, yes. There's another serious but less
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    common exposure to X-rays. X-ray energy radiation actually causes
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    a nick in the DNA backbone, cutting it into
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    two pieces essentially separating a chromosome into two pieces.
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    >> That sounds like really bad news, Matt.
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    >> It can be. Most of the time your cells are
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    able to immediately attach the Chromosome back together. But because it's
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    such a big deal, your cells will try to attach it really quickly
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    and anything it can find. Remember, there's not a lot of space in your
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    cells and the DNA is packed really close together. This means that sometimes a
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    chromosome piece breaks off and gets attached
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    to a whole other chromosome, like this.
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    >> So the information is still
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    preserved, it's just rearranged onto different chromosomes.
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    >> Exactly, and we call this a Translocation.
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    >> But if all the
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    information is still there, why is it a problem?
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    >> Well, sometimes all the information, it turns out,
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    is not there, but even if it is think of
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    all the problems you could run into with rearranged information.
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    Let's take this chromosome pair where there's one gene in
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    orange at the end and then another chromosome pair where
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    there's this gene in pink at the end. Now let's
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    say there's a chromosome break in each chromosome and that
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    happens right in the middle of the two respective genes.
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    And just by sheer random chance. Now let's say these chromosome pieces swap
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    to the genes lands at exactly in frame with each other's coding region. What
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    do you think the most likely result
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    will be? Let's assume that everything swapped
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    in frame. I want you to select the answer that you think is best.
タイトル:
21_l
Video Language:
English
Team:
Udacity
プロジェクト:
BIO110 - Tales from the Genome
Duration:
01:38
Cogi-Admin edited 英語(米国) subtitles for 21_l

English subtitles

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