Who discovered and developed the double helix model of DNA?

Who discovered and developed the double helix model of DNA?

• A. Watson and Crick
• B. Hershey and Chase
• C. Chargaff
• D. Rosalind Franklin

Answer: (A)

Understanding why the double helix was proposed comes from linking base composition data to a concrete three-dimensional model. James Watson and Francis Crick put forward the correct structure in 1953: a right-handed double helix with two antiparallel strands and a sugar–phosphate backbone on the outside, while the paired bases stack inside the helix. This arrangement naturally explains Chargaff’s rules, which show that A pairs with T and G pairs with C, enabling accurate replication because each strand can serve as a template for the other. Their model also built on crucial X-ray diffraction data collected by Rosalind Franklin and Maurice Wilkins, which indicated a helical shape and specific dimensions, and it integrated Chargaff’s base-pairing insight. Hershey and Chase addressed whether DNA or protein carries genetic information, not the structure of DNA, so their work isn’t about who discovered the double helix. Rosalind Franklin’s data were essential to shaping the correct model, but the credit for discovering and developing the double helix is attributed to Watson and Crick.

Understanding why the double helix was proposed comes from linking base composition data to a concrete three-dimensional model. James Watson and Francis Crick put forward the correct structure in 1953: a right-handed double helix with two antiparallel strands and a sugar–phosphate backbone on the outside, while the paired bases stack inside the helix. This arrangement naturally explains Chargaff’s rules, which show that A pairs with T and G pairs with C, enabling accurate replication because each strand can serve as a template for the other. Their model also built on crucial X-ray diffraction data collected by Rosalind Franklin and Maurice Wilkins, which indicated a helical shape and specific dimensions, and it integrated Chargaff’s base-pairing insight. Hershey and Chase addressed whether DNA or protein carries genetic information, not the structure of DNA, so their work isn’t about who discovered the double helix. Rosalind Franklin’s data were essential to shaping the correct model, but the credit for discovering and developing the double helix is attributed to Watson and Crick.