In sea urchin DNA, which is double stranded, 17% of the bases were show to be cytosine. The percentages of the other three bases expected to be present in this DNA are

Options

A. G/34%, A/24.5%, T/24.5%
B. G/17%, A/16.5%, 5/32%
C. G/17%, A/33%,T/33%
D. G/8.5%, A/50%, T/24.5%

Answer

C

Explanation

Chargaff's rule states that purine and pyrimidine bese pairs are present in equal amount in dsDNA, i.e A = T,G = C
`(A+T)/(G+C)=1`
If cytosine = 17%
If A + G + C + T = 100 and G =C, A=T
Then A + 17 +17 + T = 100
A+T+34=100
A+T=100-34
A +T =66
A=T= `(66)/(2)` =33% Hence, ifcytosine is 17%thenG=17% and A and T will be 33% each