To the untrained eye Rosalind Franklin’s Photo 51 was simply a grainy black-and-white image of dark marks scattered in a rough X shape. But to the eye of a trained scientist it was a clear portrait of a DNA fiber taken with X-rays. And to young scientists James Watson and Francis Crick it helped answer a great mystery - how do organisms live grow develop and survive generation after generation This simple picture would change the way scientists viewed life itself.