Which of the following base is not present in D.N.A.?
AAdenine
BGuanine
CThymine
DUracil
Answer:
D. Uracil
Read Explanation:
DNA Nitrogenous Bases
Deoxyribonucleic acid (DNA) is composed of four primary nitrogenous bases: Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).
These bases are categorized into two groups based on their chemical structure: Purines (Adenine and Guanine) and Pyrimidines (Cytosine and Thymine).
Uracil (U) is a nitrogenous base that is exclusive to RNA (Ribonucleic acid) and is not found in DNA molecules under normal physiological conditions.
In RNA, Uracil replaces Thymine, meaning RNA contains Adenine, Guanine, Cytosine, and Uracil.