question_answer 63)

  You are repeating the Hershey-Chase experiment and are provided with two isotopes32P and15N (in place of 35S in the original experiment). How does you expect your results to be different?

Answer:

                  Use of 15N will be inappropriate because method of detection of 32P and 15N different (32P being a radioactive isotope while15N is non-radioactive but is the heavier isotope of nitrogen). Even if15N was radioactive then its presence would have been detected, both inside the cell(15N incorporated as introgenous base in DNA) as well as in the supernatant, because15N would also get incorporated in amino group of amino acids in proteins. Hence, the use of 15N would not give any conclusive results.