In humans, myopia prevails over normal vision, and brown eye color over blue. The only child of myopic

In humans, myopia prevails over normal vision, and brown eye color over blue. The only child of myopic brown-eyed parents has blue eyes and normal vision. Determine the genotype of all family members

Let’s designate the gene that determines the myopia of a person as B, then the corresponding gene that determines the development of normal visual acuity will be designated b.

Let’s designate the gene for brown eyes as K, then the gene for blue eyes will be k.

The child has blue eyes and normal vision. Let’s write it bbkk, because both of these traits can be realized phenotypically only being in a homozygous state.

This genotype also indicates the presence of recessive traits (b and k) in the genotypes of both genes in both parents.

Parents have brown eyes and myopia (genes B and K), therefore, they carry the genes for blue eyes and normal vision (b and k) in a latent form, that is, both are heterozygotes.

Let’s write the parents like this – BbKk.

Answer: parents are diheterozygotes (BbKk), the child is dihomozygote for recessive genes (bbkk).