question_answer 26)

  Who amongst the following scientists had no contribution in the development of the double helix model for the structure of DNA? (a) Rosalind Franklin       (b) Maurice Wilkins         (c) Erwin Chargaff                            (d) Meselson and Stahl

Answer:

                  (d) It was only in 1953 that James Watson and Francis Crick, based on the X-ray diffraction data produced by Maurice Wilkins and Rasalind Franklin, proposed a very simple but famous double helix model for the structure of DNA. Erwin Chargaff observed that for a double-stranded DNA, the ratios between adenine and thymine and guanine and cytosine are constant and equals one. On the other bond Matthew Meselson and Franklin Stahl in 1958 performed experiments on E.coli to prove that DNA replication is semi-conservative. But had no contribution it the development of double helix model.