DNA being carried by each chromosome

[leah3000]

Hi

I'm a little bit confused in terms of the DNA being carried by each chromosome.

When the cell is described as 4n in Interphase; with 4 copies of each DNA molecule, does this mean that each chromatid has 1 molecule of DNA? Hence, allowing 2molecules of DNA per chromosome?

Also can someone explain how the cell goes from 4n to 2n in Anaphase?

 

[mazinse]

Yes one chromatid is an entire double helix by itself. from 4n to 2n, well since you already mentioned anaphase, don't you think you know the answer already

 

[leah3000]

ok...I think I was looking at the diagrams and sort of confused myself. Now that I think about it 4n would just mean doubling the DNA so that the cell can divide into 2 daughter cells. It wouldn't necessarily mean 2 chromosomes which would give the 4 DNA molecules.

So then 2n would just mean the DNA distributed to the daughter cells...is that correct?

 

[mazinse]

yeah you got it, the n vs 2n thing is just a haploid vs diploid thing

 

[leah3000]

cool. Thanks very much for your help