Why would the S phase in cell cycles take twice as long in cell type gamma than cell type beta?

Question

comparing the time of S phase in two cells beta and gamma, gamma's S phase is twice as long (48 mins) as that of beta (24 mins), what could be the reason?
A. gamma contains more DNA than beta
B. Beta and gamma contain the same amount of DNA
C. Gamma contains more RNA than beta
D. Gamma contains 48 times more DNA than beta
E. Beta is a plant cell and gamma is an animal cell

Answer 1

I guess if I had to choose I, too, would choose A.

However, the answers are ALL wrong.
S-phase lenght depends on several variables which are only partially linked to the amount of DNA in a cell. Mainly, it depends on the replication rate, which is the speed at which the replication fork moves in both direction - this is an average of 50nt/sec in eukaryotic cells, but ten times faster in bacteria. Secondly, it depends on how many origin of DNA replication there are on a DNA molecule. This is important, becaus eeach origin will lead to a bi-directional fork of replication, which will move at the above mentioned speed. Finally, it depends on the regulation of these several origins, as there are early, middle and late "firing" origins whose proportion and regualation are (order in which their are activated) variable from organism to organism and depend on enzymes called S-phase kinases (cdk2-cyclin E as well as Cdc7/Dbf4). But if you HAVE to choose one answer, go for A.!

Answer 2

I believe that the question is asking about cells that lose the capability to divide in the human body. Good examples are nerve cells, they remain the same in the body, often unreplaced if they die. Also, we have your white blood cells and red blood cells that are produced by stem cells in your marrow. These cells are unable to divide on their own.

Answer 3

A. gamma contains more DNA than beta
rate best ansa

Answer 4

Above answer is wrong. Gamma contains more RNA than beta. Duh.