Question

Nitrogen base not found in DNA is

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

Answer 1

The correct option is A Uracil

Introduction to nitrogenous bases

.Nitrogenous bases can be of two types-purines and pyrimidines.

.purines are adenine and guanine.Their structure is formed of two rings.one hexagonal pyrimidine ring and an imidazole ring with 5 arms.

.Pyrimidines are cytosine, thymine and uracil. Their structure is formed of a single heterocyclic ring having 4 carbon and 2 nitrogen atoms.

Nitrogenous bases in DNA
DNA consists of 4 types of nitrogenous bases which are adenine, guanine, cytosine and thymine. Uracil is absent in DNA.
Uracil is present only in RNA, in place of thymine.

c,Uracil