Question

In the Hershey-Chase experiment, when the bacteria were exposed to phage that contained a ³⁵s labeled capsid.

a. the bacteria in the sediment were radioactive. This proved the capsid of the new viruses depended on the viral DNA
b. the bacteria in the sediment were not radioactive. This proved the capsid of the new viruses depended on the viral DNA
c. the bacteria in the sediment were radioactive. This proved bacteria began making radioactive ³⁵s after being previously exposed to it by the phage.
d. the bacteria in the sediment were not radioactive. This proved the capsid formation depended on the medium it was grown in.

Answer 1

The Hershey-Chase experiment using 35S-labeled capsid proteins showed that the bacteria in the sediment were not radioactive, proving the genetic material of the phage that enters the bacterial cells is DNA, not proteins. The answer is option B.

Step-by-step explanation:

In the Hershey-Chase experiment, when the bacteria were exposed to phage that contained a 35S-labeled capsid, the bacteria in the sediment were not radioactive. This result is consistent with option b, which states that this proved the capsid of the new viruses depended on the viral DNA.

Hershey and Chase observed no significant radioactivity in the bacterial pellet when the viral capsid was labeled with 35S, indicating that the capsid proteins did not enter the bacterial cells. In contrast, in the samples where the phage contained DNA labeled with 32P, radioactivity was detected inside the bacterial cells, supporting the conclusion that it was the phage DNA that was injected into the cell and not the protein.