Question

In Hershey and Chase experiment radioactive $S^{35}$ detected in
A. Supernatant
B. Pellet
C. Both
D. None

Answer 1

Hint: In 1952, Alfred Hershey and Martha Chase thought of utilizing a technique named radioactive isotope labeling for their experiment. The virus named bacteriophage T2 was used which was responsible for infecting bacteria.

Complete answer:
The experiment starts with the culturing of viruses in two types of medium. One set of viruses i.e $(S^1)$was cultured in a medium of radioactive phosphorus whereas another set of viruses i.e $(S^2)$ was cultured in a medium of radioactive sulfur $(S^{35})$. They observed $(S^1)$ virus which contains radioactive DNA but not radioactive proteins. This is because DNA is a phosphorus-based compound while protein is not a phosphorus-based. The latter set of viruses $(S^2)$ consisted of radioactive protein but not radioactive DNA.
The host for infection was E.coli bacteria. The viruses were allowed to infect bacteria by removing the viral coats by using several blending and centrifugation.

Supernatant - Bacteria with $S^{35}$ virus was not found infected and was present in the supernatant while $P^{32}$ was infected and was not found in the supernatant.

Hence, the correct answer is option (A).

Additional information:
The Griffith’s experiment and some other experiments are followed to discover the hereditary material in organisms. Based on Griffith’s experiment, Avery and his team isolated the DNA and proved DNA is the genetic material in living organisms and viruses. But it was not accepted by all because the Griffith experiment was done in 1928.so until Hershey and Chase published their experimental results.

Note: From the Hershey and Chase experiment, we can observe E.coli bacteria that were infected by radioactive DNA viruses $(S^1)$ were radioactive but the ones that were infected by radioactive protein viruses $(S^2)$ were non-radioactive. As a result, radioactive and non-radioactive bacteria infer that the viruses that had radioactive DNA transferred their DNA to the bacteria but viruses that had radioactive protein didn’t get transferred to the bacteria. Hence, DNA is the genetic material.