In the Meselson-Stahl experiment, 15N-labeled cells were shifted to 14N medium at what is designated as generation 0. For the conservative model of replication, what proportion of 15N-15N, 15N- 14N, and 14N-14N would you expect to find after one replication cycle?

½ 15N-15N and ½ 14N-14N

Explanation:

The conservative model of replication is was postulated as the process in which an intact/whole double helix acts as a template for a newly synthesized double helix. According to Messelson-Stahl experiment, after the first round of replication, the parents strand which is the 15N-15N will act as a template to form the new strand which is the 14N-14N after taking up this form of nitrogen. Thus we have one whole double helix parental 15N-15N and one newly synthesized double helix 14N-14N. There would be no combination of the two.