Question

According to Chargaff's Rule, what is the relationship between purines and pyrimidines in DNA?

Options

• The amount of purines always equals the amount of pyrimidines

• There is no consistent relationship between purines and pyrimidines

• Purines are always twice the amount of pyrimidines

• Pyrimidines are always twice the amount of purines

Answer 1

Chargaff's Rule (1950) states that in DNA, the amount of purines always equals the amount of pyrimidines. Additionally, the base ratio (A+T / G+C) remains constant for a particular species. This rule was crucial in supporting the Watson and Crick double helix model.