Question

In DNA, the complimentary bases are

(a) adenine and guanine; thymine and cytosine

(b) uracil and adenine; cytosine and guanine

(c) adenine and thymine; guanine and cytosine

(d) adenine and thymine; guanine and uracil.

Answer 1

Correct option (c) adenine and thymine; guanine and cytosine

Explanation :

DNA contains two types of nitrogenous bases

Purine → Adenine (A) and guanine (G)

Pyrimidine → Cytosine (C) and thymine (T)

The purine and pyrimidine bases pair only in certain combination. Adenine pairs with thymine (A: T) by two hydrogen bonds and guanine with cytosine (G: C) by three hydrogen bonds.