Question

Choose the correct answers from the alternatives given :
What are the base-pairing rules for DNA?

• A. A-G, T-C
• B. A-T, G-C
• C. A-U, C-G
• D. A-C, T-G

Answer 1

The correct option is B A-T, G-C

Nitrogenous bases are essentially of two types

1. Purines {adenine(A) and guanine(G)}, and
2. Pyrimidines {thymine(T), cytosine(C), and uracil(U)}.

As per the base pairing rule in DNA, A bonds to T with double bonds, G bonds to C with triple bonds and vice versa. While in RNA, A bonds to U, G bonds to C and vice versa with double and triple bonds respectively.

So, the correct option is 'A-T, G-C'.