The number of nucleotides for each type of gene B can be calculated as follows: - Given that G = 2A, we can substitute this value into the equation to find the number of A nucleotides: A = (2040/3.4) * (20/100) = 120. - Since G = 2A, the number of G nucleotides is twice the number of A nucleotides: G = 2 * 120 = 240. - The total number of nucleotides in gene B is the sum of the number of A and G nucleotides: B = A + G = 120 + 240 = 360. Regarding the mutation from gene B to gene b, where the length changes to R0 and the number of hydrogen bonds increases by 1, we cannot determine the exact number of nucleotides for gene b without additional information.