The yellow color of the fur of wild mice dominates over the gray agouti. homozygous yellow

The yellow color of the fur of wild mice dominates over the gray agouti. homozygous yellow mice die before birth (lethal genes). what is the% probability of agouti mice when crossing yellow mice with each other?

Let us denote the gene for yellow coloration A, and the gene for gray – a. A homozygous individual with a yellow color, which turns out to be unviable, has the AA genotype. Heterozygous Aa mice with a yellow color are viable.

When they are crossed, the offspring will have the following genotypes: AA, Aa, aa. Moreover, these genotypes are inherited with a probability: 1: 2: 1. However, mice with the AA genotype die before birth. Thus, with a probability of 1 in 3, gray agouti mice are born.