Meselson and Stahl were trying to determine if DNA replication was semiconservative, conservative, or dispersive by labeling E. coli DNA with a regimen of heavy nitrogen (H) for one round of replication and then transferring these cells to light nitrogen (L) for two more rounds of replication. Which of the following statements would not be true within the context of this experiment?
A) If DNA replication were conservative, no DNA molecules of intermediate density (H-L) would have been seen.
B) If DNA replication were dispersive, only DNA molecules that were of intermediate density (H-L) would have been seen.
C) If DNA replication were semiconservative, the DNA molecules that were made would all continue to be heavy density (H-H).
D) If DNA replication were semiconservative, the DNA molecules would consist of one parental strand basepaired to one newly replicated strand.
E) If DNA replication were semiconserative, a higher proportion of DNA molecules from future divisions would have been low density (L-L).

Question

Meselson and Stahl were trying to determine if DNA replication was semiconservative, conservative, or dispersive by labeling E. coli DNA with a regimen of heavy nitrogen (H) for one round of replication and then transferring these cells to light nitrogen (L) for two more rounds of replication. Which of the following statements would not be true within the context of this experiment?
A) If DNA replication were conservative, no DNA molecules of intermediate density (H-L) would have been seen.
B) If DNA replication were dispersive, only DNA molecules that were of intermediate density (H-L) would have been seen.
C) If DNA replication were semiconservative, the DNA molecules that were made would all continue to be heavy density (H-H).
D) If DNA replication were semiconservative, the DNA molecules would consist of one parental strand base­paired to one newly replicated strand.
E) If DNA replication were semiconserative, a higher proportion of DNA molecules from future divisions would have been low density (L-L).

Quizplus · Accepted Answer

If DNA replication were semiconservative, the DNA molecules that were made would not all continue to be heavy density (H-H), as the original heavy nitrogen labeled strands would be distributed among both daughter strands in subsequent rounds of replication resulting in both heavy and light density DNA molecules.

Meselson and Stahl Were Trying to Determine If DNA Replication