If Adenine makes 30% of the DNA molecule, what will be the percentage of Thymine, Guanine and Cytosine in it?
- T : 20 ; G : 25 ; C : 25
- T : 20 ; G : 30 ; C : 20
- T : 20 ; G : 20 ; C : 30
- T : 30 ; G : 20 ; C : 20
Answer
(4) T : 30 ; G : 20 ; C : 20
Solution
By Chargaff's rule, in double-stranded DNA A = T and G = C.
⇒ T = A = 30%
⇒ G + C = 100% − (A + T) = 100% − 60% = 40%
∴ G = C = 20%
Answer: (4)