How does interphase prepare cells for mitosis?

A biochemist measured the amount of DNA in cells growing in the laboratory and found that the quantity of DNA in a cell doubled

a. Between prophase and anaphase of mitosis

b. Between the G1 and G2 phases of the cell cycle

c. During the M phase of the cell cycle

d. Between prophase I and prophase II of meiosis

A particular cell type spends 4 hours in G1 phase, 2 hours in S-phase, 2 hours in G2 phase, and 30 minutes in M-phase. If a pulse-chase experiment were performed with radioactive thymidine on an asynchronous culture of such cells, what percentage of mitotic cells would be radiolabeled 9 hours after the pulse?

a. 0 percent

b. 50 percent

c. 75 percent

d. 100 percent

If a cell at G₁ contains four picograms of DNA, how many picograms of DNA will it contain at the end of the S phase of the cell cycle?

a. 0

b. 2

c. 4

d. 8