In the Meselson-Stahl experiment, the conservative model of DNA replication was ruled out by which of the following observations?
A) No completely "heavy" DNA was observed after the first round of replication.
B) No completely "light" DNA ever appeared, even after several replications.
C) The product that accumulated after two rounds of replication was completely "heavy."
D) Completely "heavy" DNA was observed throughout the experiment.
E) Three different DNA densities were observed after a single round of replication.

Question

Quizplus · Accepted Answer

The conservative model would predict that after the first round of replication, there would be one completely "heavy" DNA molecule and one completely "light" DNA molecule. The absence of completely "heavy" DNA after the first round ruled out the conservative model.

In the Meselson-Stahl Experiment, the Conservative Model of DNA Replication