Describe the contributions made by James Watson and Francis Crick and Rosalind Franklin and Maurice Wilkins to the discovery of the structure of DNA

Chargaff's realization that A = T and C = G, combined with some crucially important X-ray crystallography work by English researchers Rosalind Franklin and Maurice Wilkins, contributed to Watson and Crick's derivation of the three-dimensional, double-helical model for the structure of DNA. Franklin is best known for her work on the X-ray diffraction images of DNA while at King's College London, particularly Photo 51, which led to the discovery of the DNA double helix for which Francis Crick, James Watson, and Maurice Wilkins shared the Nobel Prize in Physiology or Medicine in 1962.

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