Question

Choose the correct answer from the alternatives given :
Watson and Crick (1953) proposed DNA double helix model and won the Nobel Prize; their model of DNA was based on
(i) X-ray diffraction studies of DNA done by Wilkins and Franklin
(ii) Chargaffs base equivalence rule
(iii) Griffiths transformation experiment
(iv) Meselson and Stahls experiment.

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

Answer 1

The correct option is B (i) and (ii)

In 1953, James Watson and Francis Crick based on the X-ray diffraction data produced by Maurice Wilkins and Rosalind Franklin, proposed double helix model for the structure of DNA. One of the hallmarks of their proposition was base pairing between two strands of polynucleotide chains. However, this proportion was also based on the observation of Erwin Chargaff (1950) that for a double stranded DNA, the ratios between Adenine and Thymine and Guanine and Cytosine are constant and equals one.

So, the correct answer is '(i) and (ii)'.