Question

Parents that are heterozygous for having freckles (dominant) are crossed. Which represents the ratio of their offspring?

Answer 1

In a cross of parents heterozygous for having freckles, the ratio of their offspring is (C) Seventy-five percent have freckles. Let allele F be dominant and allele f be recessive. Heterozygous parents will have genotype Ff. After they cross (Ff x Ff), the offspring will be: 1 FF (with freckles), 2 Ff (with freckles), and 1 ff (without freckles). So, 3 out of 4 children will have freckles. Since 3/4 = 0.75 = 75%, 75% of offspring will have freckles.

Answer 2

The answer to the question is C, the one that represents the ratio of their offspring is seventy-five percent have freckles. Since the genotypes of the posterity are FF, Ff, Ff, and ff. Since spots (capital F) are prevailing, and they are in 3 out of 4 of the genotypes, 75% will have spots.