Question

If Meselson and Stahl had used CsCl gradient analysis and identified DNA molecules with two distinct densities after the first generation, which model of DNA replication would have been supported by this data?
O conservative replication model
O semiconservative replication model
O dispersive DNA replication model

Answer 1

Answer:

conservative replication model

Explanation:

In their experiment, Meselson and Stahl found that the DNA duplexes present after the first round of replication had intermediate density. This occurred since the semiconservative process of DNA replication of one DNA molecule (having both strands with 15N) forms two DNA duplexes each with one parental strand (15N) and one newly formed strand (14N).

If they had found two duplexes of two different density, this would have supported the conservative replication model. In this case, the DNA replication of the parent DNA molecule would have formed two DNA duplexes. One DNA molecule would have both the parental DNA strands with 15N while the other DNA duplex would have both newly formed strands with 14N.