He is best known for
his discovery of the structure of DNA for which he shared with
Francis Crick and Maurice Wilkins the 1962 Nobel  prize in
Physiology and Medicine They proposed that DNA molecule takes
the shape of a double helix, an elegantly simple structure that
resembles a gently twisted ladder The rails of the ladder are
made of alternating units of phosphate and the sugar deoxyribose;
the rungs are each composed of a pair of  purine/ pyrimidine bases This
research laid the foundation for the emerging field of molecular biology