DNA is composed of four nucleosides: adenosine, cytidine, thymidine, and guanosine. If scientists introduced radioactive thymidine into the growth medium of the cells, it would be incorporated into the DNA molecule A) at any point in the cell cycle. B) during DNA replication. C) as the cell enters G₁of interphase. D) when centromeres split so the two chromosomes can be separated.

Question

Quizplus · Accepted Answer

Radioactive thymidine would most likely be incorporated into the DNA molecule during DNA replication, when new nucleotides are being added to the growing DNA strands. It would not necessarily be incorporated at any point in the cell cycle, and is not dependent on the splitting of centromeres. Incorporation during the G1 to S phase transition is also a possibility, but DNA replication is the most likely event.

DNA Is Composed of Four Nucleosides: Adenosine, Cytidine, Thymidine, and Guanosine