Consider that a double stranded DNA has 15% Guanine . What will be the % of Thymine? Explain?

Acc. To Chargaffs rule the ratio of Purines : Pyrimidines is a constant in a double strand ed DNA for a given species . % of  A = T & that of C= G

G = 15% so C = 15%

G + C = 30%

Total = 100%

A+ T = 100 – 30%  = 70%

A=T , so , 70% divided by 2 = 35% each