What number of chromosomes does the cell have in each phase of its cycle?

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Sara_Acton
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#1
Report Thread starter 2 years ago
#1
And what do we mean by "a full set if DNA"? Is it always 46 chromosomes?

(I'm asking in mitosis in human)

Thanks !!
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stepheds
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#2
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A full set of dna is 23 identical pairs of chromosomes so 46 in total.
After mitosis, each daughter cell will be IDENTICAL to the parent cell so each will have 46.

It’s always 46 unless you’re assay is also asking for when it wouldn’t be. That’s when you can look into conditions such as Down syndrome which results in 47 chromosomes, so on chromosome 21, instead of 2 there are 3 copies.
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Renn0
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#3
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Yea, stepheds right.
There are always 46 chromosomes in the cell no matter what stage of the cell cycle it's in. However, the number of chromatids changes. (maybe you were getting mixed up with chromatids?)

During interphase (the first stage), all of the DNA in the cell replicates prior to mitosis (the second stage). Originally before interphase there were 46 chromosomes and 46 chromatids. However after interphase there should still be 46 chromosomes, but 92 chromatids (because the DNA is duplicated).

During mitosis these numbers stay constant until 2 daughter cells are produced in the third stage, nuclear division, where the chromatid number returns back to 46 in each daughter cell. (throughout these stages chromosome number is always 46).

Image
This is a good diagram. Hope this helps in some way
Last edited by Renn0; 2 years ago
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