If content of A is 15%, what is the
amount of G in DNA according to
Chargaff s rule?
a) 15%
b) 85%
c) 35%
d) 70%
Correct Answer - C
Ans. is ‘c’ i.e., 35% [Ref Harper’s Illustrated biochemistry 27th/e
p. 311-313]
Chargaff’s rule:
Amount of purine = Amount of pyrimidine (A + G = T + C) Also
A+G+T+C= 100
Since A = T, Therefore 15 + G + 15 + C = 100
Since G = C, Therefore 30, + 2G = 100
2G = 70 4 G = 35