Question

In Hershey and chase, Experiment, what finding led to the conclusion that DNA is the genetic material.

• A. The presence of radioactivity in the bacteria when $355$ was used
• B. The presence of radioactivity in the supernatant when $355$ was used
• C. The presence of radioactivity in the bacteria when $32$P was used
• D. The presence of radioactivity in the supernatant when $32$P was used

Answer 1

The correct option is C The presence of radioactivity in the bacteria when $32$P was used

• The Hershey-Chase experiment began with the culturing of viruses in two types of medium. One set of viruses (A) was cultured in a medium of radioactive phosphorus whereas another set (B) was cultured in a medium of radioactive sulfur.
  
• They observed that the first set of viruses (A) consisted of radioactive DNA but not radioactive proteins. This is because DNA is a phosphorus-based compound while protein is not. The latter set of viruses (B) consisted of radioactive protein but not radioactive DNA.
  
• Resultant 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 and not the protein.
  

So, the correct option is 'The presence of radioactivity in the bacteria when 32P was used'.