Question

The fact that DNA is a genetic material was established by the experiment of

• A. Meselson and Stahl
• B. Hershey and Chase
• C. Avery, Macleod and McCarty
• D. Rosalind Franklin and Kornberg

Answer 1

Answer: (B)

Hershey and Chase

The experiment of Hershey and Chase by bacteriophage first time proved that DNA is a genetic material. The experiment included the following step:

1) The DNA of the phage was labelled by radioactive phosphorous, p-32 while the protein coat was labelled by S-32 phage.

2) The labelled bacteria was allowed to inject the unlabelled bacterial host.

3) The genetic material of the progeny was analysed.

4) The genetic material of the progeny was found labelled with p-32.

5) Thus, it was concluded that it is DNA, not the protein coat which acts as genetic material.

So, the correct answer is option B.