Question

The pyrimidine bases present in DNA are
(a) cytosine and thymine
(b) cytosine and uracil
(c) cytosine and adenine
(d) cytosine and guanine

Answer 1

Answer:

(d) cytosine and guanine

Answer 2

(a) cytosine and thymine

Explanation:

The purines in DNA are adenine and guanine, the same as in RNA. The pyrimidines in DNA are cytosine and thymine; in RNA, they are cytosine and uracil. Purines are larger than pyrimidines because they have a two-ring structure while pyrimidines only have a single ring.

Option A is the answer.