Question

The purine base present in RNA is
A.Guanine
B.Thymine
C.Cytosine
D.Uracil

Answer 1

To answer this question, we should have knowledge on the structures of DNA (deoxy ribonucleic acid) and RNA (ribonucleic acid). Purine and pyrimidine are the nitrogenous bases that are present in nucleic acids.

Complete step by step answer:
-The nitrogenous bases are of two types – purine and pyrimidine. Purine bases are six membered and pyrimidine bases are the five membered nitrogen containing ring compounds.
-Purine bases are again of two types – adenine (A) or 6-amino purine and guanine (G) or 2-amino-6-oxy purine.
-Pyrimidine bases are of three types – thymine (T) or 2,4-dioxy-5-methyl pyrimidine, cytosine (C) or 2-oxy-4-amino pyrimidine and uracil (U) or 2,4-dioxy pyrimidine.
-In DNA adenine (A), thymine (T), guanine (G) and cytosine (C) are present.
-In RNA uracil or U is present instead of thymine (T).
-Adenine (A) and thymine (T) form two hydrogen bonds between them.
-Guanine (G) and cytosine (C) form three hydrogen bonds between them.
So, in RNA the purine base present is Guanine.

Hence, for this question, the correct answer is option A. Guanine.

Additional information: DNA and RNAs are composed of nitrogenous bases (purines and pyrimidines) along with phosphate and sugar also called nucleotides, whereas if phosphates are not present the unit is called nucleoside. DNA and RNA nucleotides are important for any organism for protein synthesis and to transfer the genetic information through reproduction.

Note:
Remember the basic differences between DNA and RNA. Uracil is only present in case of RNA. RNA is a single stranded structure while DNA has a double helix structure. Both of these nucleic acids serve as the hereditary unit.