Suppose you are provided with an actively dividing culture of Escherichia coli bacteria to which radioactive thymine has been added.What would happen if a cell replicates once in the presence of this radioactive base?
A)One of the daughter cells,but not the other,would have radioactive DNA.
B)Neither of the two daughter cells would be radioactive.
C)All four bases of the DNA would be radioactive.
D)DNA in both daughter cells would be radioactive.

Question

Quizplus · Accepted Answer

During DNA replication, the newly synthesized strand will contain the radioactive thymine since it was incorporated by the replicating DNA polymerase. Therefore, both daughter cells will have radioactive DNA. Option A is incorrect because both daughter cells should have radioactive DNA. Option B is incorrect because the radioactive thymine will be incorporated into the DNA in at least one of the daughter cells. Option C is incorrect because only the thymine will be radioactive, not all four bases.

Suppose You Are Provided with an Actively Dividing Culture of Escherichia