Question

DNA is the genetic material, was proved conclusively by

• A. J.D. Watson
• B. Hershey and Chase
• C. Alfred Griffith
• D. Boveri and Sutton

Answer 1

The correct option is B Hershey and Chase

Hershey and Chase conducted experiments that confirmed that DNA is the genetic material.

They showed that when bacteriophages, which are composed of DNA and proteins, infect bacteria, their DNA enters the host bacterial cell and not the protein coat. To prove this they used radiolabelled phosphorus (P-32) in the DNA and radiolabelled sulfur (S-35) in the protein coat.

The labeled phage progeny was allowed to infect the unlabelled bacteria. The phage coat remained outside the host while DNA entered. Disruption of phage from the bacteria by agitation followed by centrifugation allowed the separation of the phage coat from the bacteria. The bacteria were lysed to release the phage progeny. The new progeny produced contained radiolabelled phosphorus since DNA has phosphorous and not sulfur. Thus proved that DNA is the genetic material.

So, the correct option is 'Hershey and Chase'.