Question

Assuming we are studying a gene with two alleles, one of which is dominant to the other, what is the frequency of homozygous recessive offspring in a cross between two heterozygotes

Answer 1

The frequency of homozygous recessive offspring in a cross between two heterozygotes is 25%.

Step-by-step explanation:

Since the alleles are of two types, that is dominant and recessive alleles. An heterozygous parent will have both alleles.

So, we can represent our dominant allele with G and the recessive allele with g.

Then, the two heterozygous parents will have Gg genes.

These alleles will be segregated into their singleness. the first parent will therefore have G and g and the second parent will also have G and g

Crossing these alleles using punnet's square, we the have the following genotypic ratio of the progenies: 1GG: 2Gg: 1gg

Therefore, the 1gg is the only heterozygous offspring out of the expected four offsprings. This made the frequency to be 1/4 X 100 = 25%.