What structural property of DNA gave Watson and Crick the idea that DNA replication was likely to proceed via a semiconservative mechanism?
A.
B.
C.
D.
Correct. See Key Concept 13.2 DNA Has a Structure That Suits Its Function
Incorrect. See Key Concept 13.2 DNA Has a Structure That Suits Its Function
Animation 13.3 Quiz
If the conservative model had been correct, how many generations of bacterial cell division would have had to pass before Meselson and Stahl would have observed evidence of a band in the CsCl gradient corresponding to a hybrid DNA molecule containing both 14N and 15N?
A.
B.
C.
D.
Correct. See Key Concept 13.3 DNA Is Replicated Semiconservatively
Incorrect. See Key Concept 13.3 DNA Is Replicated Semiconservatively
Animation 13.3 Quiz
Refer to the table below.
Meselson and Stahl grew bacteria in the presence of heavy nitrogen for many generations, and then exposed the bacteria to an excess of light nitrogen, resulting in the production of generation 1. Which percentages of light, intermediate, and heavy DNA shown in the table would Meselson and Stahl have observed in their experiment?
A.
B.
C.
D.
Correct. See Key Concept 13.3 DNA Is Replicated Semiconservatively
Incorrect. See Key Concept 13.3 DNA Is Replicated Semiconservatively
Animation 13.3 Quiz
Suppose thymidine labeled with carbon-14 was added to a culture of bacteria and allowed to incubate for 20 minutes (one generation time). The DNA molecules were then isolated from the bacterial cells. If DNA replication is semiconservative, what would you observe about these molecules?
A.
B.
C.
D.
Correct. See Key Concept 13.3 DNA Is Replicated Semiconservatively
Incorrect. See Key Concept 13.3 DNA Is Replicated Semiconservatively
