Rosalind Franklin’s 1952 X-ray diffraction image of DNA, known as photo 51, led to James Watson and Francis Crick’s famous model of the double helix.
The photograph provided key information that was essential for developing a model of DNA.The diffraction pattern determined the helical nature of the double helix strands (antiparallel). The outside linings of DNA have a phosphate backbone, and codes for inheritance are inside the helix. Watson and Crick’s calculations from Franklin’s photography gave crucial parameters for the size and structure of the helix.
James Watson was shown the photo by Maurice Wilkins without Rosalind Franklin’s approval or knowledge and along with Francis Crick, Watson used characteristics and features of Photo 51 to develop the chemical model of DNA molecule.
Western Parotia (Parotia sefilata). Endemic to Indonesia, the Western Parotia is found only in the mountain forests of Vogelkop and the Wandammen Peninsula of Western New Guinea. Photographed by Nick Hobgood.