Question

Which nitrogen base is absent in DNA?

• A. Adenine
• B. Guanine
• C. Uracil
• D. Cytosine

Answer 1

The correct option is C

Uracil

The correct option is C.

Explanation of correct option:

1. The uracil is a nitrogen base of pyrimidine.
2. The uracil present in RNA(ribonucleic acid) bonds with a double hydrogen bond with Adenine while absent in DNA(Deoxyribonucleic acid).

Explanation of incorrect option:

Option A

Adenine is part of both RNA and DNA.

Option B:

The guanine nitrogen base is part of both RNA and DNA.

Option D:

The cytosine nitrogen base is part of both RNA and DNA.

Final answer: Uracil nitrogen base is absent in DNA.