Question

The unequivocal proof that DNA is the genetic material came from the experiments of

• A. Mathew Meselson and Franklin Stahl
• B. Alfred Hershey and Martha Chase
• C. Oswald Avery, Colin MacLeod and Maclyn McCarty
• D. Frederick Griffith

Answer 1

The correct option is B Alfred Hershey and Martha Chase

In the Hershey and Chase experiment, radioactive phosphorus ($32{}^{}P$) and and radioactive sulphur ($32{}^{}S$) was used to culture bacteriophages. These bacteriophages were then made to infect bacterial cells. It was seen that the bacterial cells contained radioactive viral DNA, but not radioactive viral protein because DNA contains phosphorous, but protein does not. Hence this experiment proved that the DNA, and not protein, is the genetic material passed from the virus to bacteria.