Question

Which of the following statements are false regarding 'Hershey and Chase' experiment, proving DNA is genetic material?
(i) They made use of rats.
(ii) Radioactivity was seen in supernatant for the medium that was infected by phage radiolabeled with ³²P.
(iii) Used radioisotope to label sulphur with ³⁵S in sulphur-containing amino acids.
(iv) Radioactive phages were allowed to attach to E. coli bacteria.

• A. (ii) and (iii) only
• B. (iii) and (iv)
• C. (ii), (iii) and (iv) only
• D. (i) and (ii)

Answer 1

Answer: (D)

Martha Chase and Alfred D.Harshey conducted an experiment that proved DNA is the genetic material that is inherited. In their experiment they used radioactive isotope of Sulfur $\left({35}^{}\mathrm{S}\right)$ and Phosphorus $\left({32}^{}\mathrm{P}\right)$ containing bacteriophage T2 (dsDNA) to infect a bacterium, Escherichia coli and found that the phosphorus-containing DNA of the viral particle, not the sulfur-containing protein of the viral coat, enters the host cell and serves the genetic information for viral replication. To conduct the experiment, the bacteriophage and bacteria was blended and constituents were separated by density gradient centrifugation.