Length of the DNA is 510 angstroms. Find the percentage of cytosine. Assume the number of adenine bases is 30 in that DNA.

Pitch of the DNA is 34 angstroms.Number of turns in the DNA= 510/34= 15 turnsNo. of base pairs per turn = 10bpNo. of base pairs in 15 turns- 15 X10= 150bpNo. of adenine = 30= No. of thymineTotal no. of (A+T) = 30+30= 60Total no. G+C= 300-60= 240No. of C= 240/2=120% C= (120/300) X 100= 40%.