Numeric relation in pyrimidine and purine bases in DNA

Question

Describe the numeric relation among pyrimidine and purine bases in the DNA molecule? Is that relation suitable in RNA molecules?

Answer 1

The DNA molecule is made up of two bound polynucleotide chains which form a helical structure (that is, the double helix). The binding of the two chains is among their nitrogen having bases and it always follows the following rules: adenine (A), a purine base, joins with thymine (T), a pyrimidine base, and guanine (G), a purine base, joins to cytosine (C), a pyrimidine base. Thus in one molecule of DNA there will be similar number of adenine (A) and thymine (T) and similar number of cytosine (C) and guanine (G). The amounts of purine and of pyrimidine bases then will as well be similar in a 50 percent proportion for each kind. The relation A = T and C = G, or A/T = C/G = 1, is termed as Chargaff’s relation and the pairing rules explained above are termed as Chargaff’s rules.

In RNA there are no two nucleotide chains. The RNA is a simple chain molecule and there is no essential proportionality of nitrogen having bases to form it.