Question

Which of the following statements is correct according to Chargaff’s rules?

(a) All DNA molecules contain the same proportions of A, C, G and T

(b) Single-stranded RNA molecules contain the same amount of A and U

(c) In double-stranded DNA, the amount of T equals the amount of C

(d) In double-stranded DNA, the amount of G equals the amount of C

The question was posed to me in class test.

This interesting question is from Genes, Chromosomes and Genomes topic in portion Bioenergetics, Enzymes, Metabolism, Genes, Chromosomes and Genomes of Cell Biology

Answer 1

Correct option is (d) In double-stranded DNA, the amount of G equals the amount of C

The best I can explain: Chargaff rule states that the amount of A is equal to the amount of T whereas the amount of C is equal to the amount of G. This is because during base pairing, A binds with T with two hydrogen bonds and C binds with G with three hydrogen bonds.