Question

Which statement is not correct about the results of the Hershey Chase experiment with T2 bacteriophage?
A: Radioactively labeled protein was found in the bacteria not in the phage coats
B: Radioactively labeled DNA was found in the bacteria, not in the phage coats
C: DNA was labelled with radioactive phosphorus.
D: Protein was labelled with radioactive sulfur

Answer 1

In $1952$, Alfred Hershey and Martha Chase published a series of investigations that contributed to establishing the fact that DNA represents genetic material. Hershey and Chase demonstrated in their tests that when bacteriophages, which are made up of DNA and protein, infect bacteria, their DNA enters but most of their protein does not. The discoveries of Hershey and Chase, as well as others, proved that DNA is the hereditary material. Hershey and Chase came to the conclusion that the genetic substance was DNA rather than protein. They discovered that the bacteriophage had a protective protein shell surrounding it, but it was the inside DNA that gave it the ability to reproduce inside a bacteria.

Complete answer:
Option A: The radioactive and non-radioactive bacteria that resulted suggest that viruses with radioactive DNA passed their DNA to the bacterium, whereas viruses with radioactive protein did not. As a result, DNA, not protein, is the genetic material.
So, option A is correct.
Option B: The presence of radioactive and non-radioactive bacteria suggests that viruses with radioactive DNA transferred their DNA to the bacteria, whereas viruses with radioactive protein did not. As a result, the genetic material is DNA rather than protein.
So, option B is incorrect.
Option C: Radiolabeled DNA was found in viruses growing in radioactive phosphorus $\left( {32P} \right)$ (phosphorus is present in DNA but not proteins).
So, option C is incorrect.
Option D: Radiolabelled proteins were found in viruses cultured in radioactive sulphur $\left( {35S} \right)$ (sulfur is present in proteins but not DNA).
So, option D is incorrect.

Hence, Option A is correct.

Note:
The experiment began with virus culture in two different mediums. One set of viruses (A) was cultured in radioactive phosphorus medium, whereas the other set (B) was cultured in radioactive sulphur medium. The first group of viruses (A) had radioactive DNA but no radioactive proteins, according to the researchers. This is due to the fact that DNA is phosphorus-based, but protein is not. The last group of viruses (B) contained radioactive protein but not DNA. E. coli bacteria served as the infection's host. By eliminating the viral coverings through blending and spinning, the viruses were able to infect bacteria.