In humans, myopia prevails over normal vision, and brown eyes over blue.

In humans, myopia prevails over normal vision, and brown eyes over blue. The father and mother are heterozygous for these traits. Determine the likelihood of having blue-eyed babies with normal vision and brown-eyed babies with myopia.

Let us designate the gene that determines the development of vision pathology in a person by the type of myopia as B, the gene for normal vision as b.

Let’s designate the gene that causes brown eyes in humans as C, then the gene for blue eyes will be c.

Father and mother, according to the condition, are diheterozygotes – BbCc, which corresponds to myopia and brown color of their eyes. They produce eggs and sperm of four types: bc, BC, Bc and bC.

All possible offspring of this married couple will look like this:

nearsighted children with brown eyes (BBCC, 2BbCC, 2BBCc, 4BbCc);

nearsighted children with blue eyes (2ВbСС, ВВcc);

normally seeing children with brown eyes (bbCC, 2bbCc);

normally seeing children with blue eyes (bbcc).

Blue-eyed children with normal vision – 1 genotype out of 16, or 6.25%.

Nearsighted children with brown eyes – 9 genotypes out of 16, or 56.25%.