Question

Which of the following statements is true about the Hershey-Chase experiment?

• A. R-strain contain phosphorus and thus can be labelled with radioacting phosphorus.
• B. DNA contain sulphur and can be labelled with ${}^{35}S$
• C. Most of radioactivity was found associated with cells inferted by bacteriophage having radioactive sulphur.
• D. Most or radioactivity was found associated with cell infeted by bacteriophage having radioctive phosphorus.

Answer 1

The correct option is D

Most or radioactivity was found associated with cell infeted by bacteriophage having radioctive phosphorus.

Proteins contain sulphur but no phosphorus whereas DNA contains phosphorus but no sulphur. Hence, both proteins and DNA can be differentially labelled using radioactive sulphur and phosphorus. Since only DNA enters the bacteria, most of the radioactivity was found in bacteria infected by bacteriophage having radioactive phosphorus.