Who co-discovered the structure of DNA?

• A. Rosalind Franklin
• B. James Watson and Francis Crick
• C. Linus Pauling
• D. Maurice Wilkins

Answer: (B)

Understanding how DNA carries genetic information works best when you see how evidence fits into a working model. Watson and Crick are credited with co-discovering the DNA structure because they proposed and published the correct double-helix model that explained how genetic information could be stored and replicated. Their model fit key ideas known at the time, including Chargaff’s rules about base pairing (A with T, G with C) and the important X-ray diffraction data that suggested a helical shape and specific dimensions. Rosalind Franklin provided crucial X-ray images that revealed the helix-like nature and certain structural details, which guided the thinking behind the model, while Maurice Wilkins shared his data to support the collaborative effort. Linus Pauling had suggested a different, ultimately incorrect structure earlier, so his approach did not yield the correct model for DNA. In short, the double-helix structure was established through Watson and Crick’s successful model construction, built on evidence from Franklin, Wilkins, and Chargaff.