Radioactive thymine is added to media containing one actively dividing E. coli bacterium. Which of the following outcomes would be seen after a single cell division?
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, new nucleotides are added to both strands of the original DNA molecule. If radioactive thymine is present in the media, it will be incorporated into the new DNA strands of both daughter cells as they replicate their DNA, making the DNA in both daughter cells radioactive.

Radioactive Thymine Is Added to Media Containing One Actively Dividing