In sheep, the gene that determines the gray color and dominates over the black color, in a homozygous state

In sheep, the gene that determines the gray color and dominates over the black color, in a homozygous state, leads to underdevelopment of the stomach, such individuals are lethal. Two heterozygous gray sheep were crossed. Determine the genotypes of the offspring. Will there be death of individuals among them?

Let’s designate the gene that determines the gray color of wool in sheep as B, then the gene that causes the development of black wool will be b.

Heterozygous sheep will be recorded as Bb, they, as stated in the condition, will have gray wool. Such sheep produce b and B germ cells.

Potential offspring will look like this:

50% of the lambs will have a gray coat (Bb);

25% of lambs will have black wool (bb);

25% of lambs will die from underdevelopment of the stomach, since their genotype will be lethal – BB.