To prove that DNA is the genetic material, which radioactive isotopes were used by Hershey and Chase (1952) in their experiments?

Options

A. `.^(35)S and .^15 N`
B. `.^(32)p and .^35 S`
C. `.^(32)p and .^15 N`
D. `.^(14)N and .^15 N`

Answer

B

Explanation

Hershey and Chase experiment is based on the fact that DNA contains phosphorus and similarly sulphur is present in proteins but not in DNA. They incorporated radioactive isotope of phosphorus `(overset(32)P)` into phage DNA and that of sulphur `(overset(35) S)` into proteins of a separate phage culture. Viruses grown in the presence of radioactive protein of radioactive phosphorus contained DNA contained radioactive DNA but not radioactive protein because DNA contains phosphorus but proteins do not . Similarly , viruses grown on radioactive sulphur contain radioactive protein but not radioactive DNA because DNA does not contain sulphur.