Final answer:
The Watson and Crick model of DNA's double helix was primarily based on Rosalind Franklin's X-ray diffraction methods. Their model showed DNA as two antiparallel nucleic acid chains forming a double helix, explaining how genetic information is encoded and replicated. This leveraged earlier work by other researchers and particularly Franklin's critical contributions.
Step-by-step explanation:
The most significant information for the derivation of the Watson and Crick model of the double helix structure of DNA was derived from X-ray diffraction methods used by Rosalind Franklin. James D. Watson and Francis Crick leveraged Franklin's X-ray diffraction images to demonstrate the helical nature of DNA, which contributed to their formulation of a double-stranded structural model of DNA. Their model revealed that DNA is composed of two nucleic acid chains running antiparallel, twisted to form a double helix, with adenine always pairing with thymine and guanine always pairing with cytosine.
The Watson and Crick model of DNA built upon the understanding that DNA can encode and pass information on to the next generation, a concept previously shown by other researchers such as Hershey and Chase. Watson and Crick's groundbreaking work brought together pieces of information from previous studies, including Chargaff's rules and the work of Franklin and Maurice Wilkins, to construct a detailed picture of DNA's secondary structure, leading to insights into the replication and inheritance mechanisms of genetic material.