Question

what would be the % of G if the % of T is 30% using chargaff's rule

Answer 1

You know that T always pairs with A. That means that for every T, there is an A. So the same total amount of T and A are present in the DNA strand. So because it tells you there is 30% of T in the strand, how much A is there?

Answer 2

30%

Answer 3

Exactly.

So you know that 30% of the molecule is T. Another 30% is A. So all told 60% of the molecule is either T or A.

Which leaves 40% of the molecule to be C and G.

But because you know that the proportion of C and G must be equal - the same way the proportion of A and T are equal - you know that the molecule must be 20% C and 20% G.

Answer 4

so g=c the amount of g would be 20?

Answer 5

thanks!