Question

A bacterium grown over medium having radioactive 35S incorporates radioactivity in:
A. Carbohydrates
B. Proteins
C. DNA
D. RNA

Answer 1

Hint: Radioactivity is a phenomenon that occurs when energetically unstable atomic nuclei spontaneously transform into more stable atomic nuclei. During the highly exoergic, statistically unpredictable, first-order process known as radioactive decay, a small amount of mass is converted to energy.

Complete step by step solution:
Hershey and Chase added the radioactive components to separate media in which bacteria were allowed to grow for 4 hours prior to the introduction of the bacteriophages. The radioactive isotopes were present in the structures of the offspring when the bacteriophages infected the bacterium. The goal of Hershey and Chase was to demonstrate what happened to the phage DNA after it left the protein coat and entered the bacteria.
The scientists permitted radioactive phages to infect bacteria by adhering to bacterial cell membranes in a liquid solution. They were aware that DNA and protein make up bacteriophage T4. They also understood that while DNA includes a significant amount of phosphorus and no sulfur, proteins contain sulfur atoms but no phosphorus. They marked and separated viral proteins from viral DNA using radioactive sulfur and phosphorus.
In general, nucleic acid (DNA) and proteins both contain phosphorus but not sulfur, and neither does sulphur. Hence To distinguish between viral protein and nucleic acid in culture medium, Hershey-Chad utilized radioactive isotopes of sulphur (S) and phosphorus (P). Only a few bacteriophages were able to thrive in bacteria that contained 35S, which was then integrated into the cysteine and methionine amino acids of proteins, resulting in the formation of the phage proteins.
So, option (B) is correct.

Note:
Hershey and Chase label the bacteriophage's center with radioactive phosphorus and its coat with radioactive sulfur. Hershey and Chase label the bacteriophage's center with radioactive phosphorus and its coat with radioactive sulfur.