Question

What are the various types of nitrogen bases found in DNA ? Name the type of bond seen between (i) two nitrogen bases of DNA (ii) phosphate and hydroxyl group of sugar of DNA.

Answer 1

Types of nitrogenous bases found in DNA are: 

(a) Adenine : Abbreviated 'A', has a 2-ring structure, so that it is a purine. 

(b) Thymine: Abbreviated T, is a pyrimidine, which. means it has a 1-ring structure. It's only present in DNA, where it pairs with adenine. 

(c) Guanine: Abbreviated 'G', is part of both DNA, where it bonds with cytosine. 

(d) Cytosine : abbreviated C, is part of DNA and bonds with guanine. It has one ring, so it's a pyrimidine. 

(i) Hydrogen bond 

(ii) Phosphodiester bond