Question

Erwin Chargaff's base equivalence rules established which of the following relationships in double-stranded DNA?

Options

• A = G and T = C

• A = C and G = T

• A + T = G + C

• A = T and G = C

Answer 1

Chargaff's rules state that in any double-stranded DNA molecule, the amount of adenine equals thymine (A = T) and the amount of guanine equals cytosine (G = C). Additionally, the total purines equal total pyrimidines (A + G = T + C). These rules were crucial for Watson and Crick to propose the double helix model.