In experiments designed as those of Hershey and Chase (1952),³⁵S was added to a virus replicating within its bacterial host.The new virions were carefully isolated and used to infect fresh bacterial cells in the absence of any radioisotopes.Where would you expect to find the ³⁵S radioisotope?
A)in the phage ghosts
B)in the bacterial matrix proteins
C)in the bacterial DNA
D)in the nucleic acid of the new virions
E)in the protein coat of the new virions

Question

Quizplus · Accepted Answer

³⁵S labels sulfur, which is found in proteins but not in DNA. In the Hershey and Chase experiment, ³⁵S was used to label the protein coat of the phage. After infection, the protein coat (phage ghosts) remains outside the bacterial cell, so the ³⁵S would be found in the phage ghosts.

In Experiments Designed as Those of Hershey and Chase (1952),³⁵S