The unequivocal proof that DNA is the genetic material came from the experiments of -
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Alfred Hershey and Martha Chase
In the Hershey and Chase experiment, when the labelled bacteriophages infected bacteria, only the radioactive DNA entered the bacteria, not the protein. So DNA is what passes from the virus to the bacteria as the genetic material.
Option (1) Frederick Griffith — Incorrect. Griffith showed transformation in Streptococcus pneumoniae, but did not find which molecule caused it.
Option (2) Alfred Hershey and Martha Chase — Correct. Their phage experiment of 1952 settled the question that Griffith’s work had left open: DNA, not protein, is the genetic material.
Option (3) Matthew Meselson and Franklin Stahl — Incorrect. Using 15N and 14N in E. coli, they proved that DNA replication is semi-conservative. Their work was on how DNA copies itself, not on whether DNA is the genetic material.
Option (4) Maurice Wilkins and Rosalind Franklin — Incorrect. They produced the X-ray diffraction data on which Watson and Crick built the double helix model.
Note: A similar question was also asked in CUET (UG) 2025 on 27-05-2025 (Slot 2) and on 20-05-2025 (Slot 2).
NCERT Extract:
The Genetic Material Is DNA – “… The unequivocal proof that DNA is the genetic material came from the experiments of Alfred Hershey and Martha Chase (1952). They worked with viruses that infect bacteria called bacteriophages.
They grew some viruses on a medium that contained radioactive phosphorus and some others on medium that contained radioactive sulfur. Viruses grown in the presence of radioactive phosphorus contained radioactive DNA but not radioactive protein because DNA contains phosphorus but protein does not.”