# Cell Cycle

1. Jul 20, 2015

### gracy

1. The problem statement, all variables and given/known data
First question of this particular page
http://www.hourlybook.com/ncert-questions-pmts-cell-cycle-cell-division/

2. Relevant equations
the answer is given as C.

3. The attempt at a solution
But i didn't understand because in last phase i.e D dna content is again reduced to 2c.But in mitosis I have studied that it is equational division so each daughter cell after mitosis should have 4C DNA content not 2C.

I think it is called equational division just because (1)number of chromosome remains same but DNA content is halved after mitosis.
(2)Each daughter cell has same number of chromosome as mother cell but half amount of DNA as compared to mother cell.
(3)Ploidy is related to number of chromosome not with DNA content
am I right?

2. Jul 20, 2015

### Ygggdrasil

The 4C refers to total DNA content, which is halved during mitosis. The original cell contains four copies of each chromosome: two identical copies of the maternal chromosome and two identical copies of the paternal chromosome. The daughter cells will each contain one copy of the maternal chromosome and one copy of the paternal chromosome. The daughter cells each have a full set of chromosomes, but the chromosomes will be present in two copies per cell rather than four copies per cell.

3. Jul 20, 2015

### gracy

4. Jul 20, 2015

### Ygggdrasil

Yes, right after cell division, the daughter cells will have the same amount of DNA as the mother cell did during the G1 phase (before DNA replication).

5. Jul 20, 2015