Question

Nucleotide constituents/nitrogen bases of RNA are
a. AGCU
b. TCXU
c. AGCT
d. CTAU

Answer 1

Hint: Nucleotides are the organic molecules that consist of nucleoside and phosphate. They are the monomeric units of the nucleic acid polymers such as deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), these both are the essential biomolecules within the life forms on the Earth.

Complete answer:
Nucleotides are basically composed of three subunit molecules which includes a nitrogenous base, a five-carbon sugar and a phosphate group which consist of one to three phosphates. The four nitrogenous bases in DNA are guanine, adenine, cytosine and thymine and in RNA are uracil, guanine, cytosine and adenine.

The nitrogenous bases of RNA are purines and pyrimidines. The adenine and guanine are the purines in the RNA and uracil and cytosine are the pyrimidines in the RNA. These rings are known as heterocyclic rings as they are composed of two elements known as nitrogen and carbon. The purines are double ring structures while the pyrimidines are the single ring structure made up of carbon and nitrogen. Purines also pair with the pyrimidines by the hydrogen bonds in the RNA molecules. The nucleotides are the basic building blocks of both DNA and RNA and are assembled by the cell one at a time and then strung together by process of replication in the DNA molecule and by process of transcription in the RNA molecules.

Hence, the correct answer is option (A).

Note: Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA is also found in nature as a single strand folded on itself rather than paired double stranded.