The DNA synthesis phase

[teenager witch]

Hello..how are you everybody?
When the cell has the whole group of chromosomes, we say it is (2n) and when it has half the group of chromosomes, it is(n).The question is when the human cell is in the DNA synthesis phase would be right to say that the cell is (4n) and has 92 chromosomes or we can't?

[mith]

I think the n number only refers to unique chromosomes so even though there is twice the amount, they're copies so you still only have 2n. However another number "c" measures mass of chromosomes. You would have a 2n 4c cell.

[teenager witch]

I believe the same....thank you for your reply.

[MrMistery]

i have heard the term "tetraploid" used for a cell which has replicated its DNA... I don't see why it is not correct.

[Darby]

It's purely a convention to consider double-stranded chromosomes to still be only single chromosomes.

[MrMistery]

to be fully accurate, the books i studied said: "although the cell is still diploid from the point of view of chromosome number it is tetraploid from the point of view of DNA molecules"