Suppose That Some Cells Are Grown in Culture in the Presence

Multiple Choice

Suppose that some cells are grown in culture in the presence of radioactive nucleotides for many generations so that both strands of every DNA molecule include radioactive nucleotides. The cells are then harvested and placed in new Moderate with nucleotides that are not radioactive so that newly synthesized DNA will not be radioactive. What proportion of DNA molecules will contain radioactivity after two rounds of replication?

A) 0
B) 1/8
C) 1/4
D) 1/3
E) 1/2