Question

Watson and Crick (1953) proposed DNA double helix model and won the Nobel Prize; their model of DNA was based on:

1. X-ray diffraction studies of DNA were done by Wilkins and Franklin.
2. Chargaff’s base equivalence rule
3. Griffith's transformation experiment
4. Meselson and Stahl's experiment

Options

• i, ii and iv

• i and ii

• iii and iv

• i, ii, iii and iv

Answer 1

i and ii

Explanation:

Based on the X-ray diffraction evidence generated by Maurice Wilkins and Rosalind Franklin, James Watson and Francis Crick suggested a double helix model for the structure of DNA in 1953. Base pairing between the two strands of polynucleotide chains was one of their main claims. This claim, however, was also supported by Erwin Chargaff's (1950) finding that the ratio of guanine to cytosine and adenine to thymine for double-stranded DNA is constant and equal to one.