Answer – The nitrogenous bases adenine (A), guanine (G), thymine (T), and cytosine are found in a strand of DNA.

Explanation:

DNA, or deoxyribonucleic acid, is the long-chain molecule that holds genetic information in most living beings. It is composed of 2 strands that run opposite each other. Each strand is further made of innumerable nucleotide units, which have 3 parts: a 5-carbon sugar, a phosphate group, and a nitrogen-containing base.

While the sugar and phosphate group form DNA’s backbone, the nitrogen bases occur at the center. Weak hydrogen bonds link the base of every nucleotide in one strand to that of the one across it.

These bases can be one of 4 types: adenine, guanine (G), thymine (T), and cytosine (C). Adenine and guanine are purines that have one 5-membered and one 6-membered nitrogen-containing ring fused together. Thymine and cytosine, on the other hand, are pyrimidine bases that each have only a single 6-membered ring. 

The bases always pair with one another in line with Chargaff’s rule. According to this rule, the pyrimidine and purine bases must have a 1:1 stoichiometric ratio in DNA. So, adenine always binds to thymine, while cytosine binds to guanine.

Nitrogenous bases are responsible for DNA’s ability to code visible traits. So when the molecule needs to duplicate itself, it unwinds through enzyme action. This causes the hydrogen bonds between the bases to break, allowing DNA replication to occur.

Popular Questions