Final answer:
Rosalind Franklin used X-ray diffraction methods to demonstrate the helical nature of DNA, while Watson and Crick formulated the double-stranded structural model of DNA.
Step-by-step explanation:
Rosalind Franklin used X-ray diffraction methods to demonstrate the helical nature of DNA, while Watson and Crick formulated the double-stranded structural model of DNA.
Franklin's X-ray diffraction images of DNA fibers provided crucial insights into the structure of DNA, which Watson and Crick used to piece together the puzzle of the DNA molecule.
The X-ray diffraction pattern showed that DNA had a helical shape, leading to Watson and Crick's proposal of the double helix structure.