Which American biochemist is associated with establishing that DNA is the genetic material and with Chargaff's base-pair rules?

• A. Watson and Crick
• B. Gregor Mendel
• C. Erwin Chargaff
• D. Rosalind Franklin

Answer: (C)

Chargaff’s base-pair rules show that DNA bases occur in complementary pairs: adenine pairs with thymine, and cytosine pairs with guanine, with each base pair present in roughly equal amounts (A ≈ T and C ≈ G) within a given organism. This pattern revealed that DNA has a predictable, specific structure that could be copied faithfully during replication, providing a molecular basis for how genetic information is stored and transmitted. Erwin Chargaff, an American biochemist, is the scientist associated with these rules. While the definitive demonstrations that DNA is the genetic material came from other experiments, Chargaff’s discovery gave a crucial framework that helped explain how DNA could carry hereditary information and be accurately replicated.