Question

As a scientist, you seek to prove that DNA is the hereditary macromolecule by replicating the Hershey-Chase experiment. You culture the lambda phage in heavy and light Cl (Cl-36 is heavy and radioactive - the most abundant is Cl-35, lighter and non-radioactive). You purify the phage from their growth media and infect the E. coli, where will you detect radioactivity?
Select one:
a. Within the E. coli pellet as the DNA has entered the bacterial cells.
b. On the E. coli cell surface (or phage fraction), as part of the phage protein coat.
c. In the supernatent (free liquid) of your test tube
d. Both A and B
e. None of the above
Why is the answer none of the above? Why cant the radioactivity be detected?

Answer 1

Answer:

The correct answer is option e. "None of the above".

Explanation:

The Hershey-Chase experiment helped to prove that DNA was the genetic material, by specifically labeling the DNA material of a bacteriophage with phosphorus-32. In this experiment the lambda phage is labeled with heavy and light Cl. CI-36, the one that is heavy and radioactive, corresponds to Chlorine-36. Chlorine is not an element found in DNA such as phosphorus, therefore lambda DNA will not be labeled and no radioactivity will be detected.