In humans, the gene for farsightedness dominates the gene for normal vision in the family

In humans, the gene for farsightedness dominates the gene for normal vision in the family, the husband and wife suffer from farsightedness, but the mothers of both spouses had normal vision. Determine the genotypes of all the persons mentioned.

Let’s designate the gene that determines the development of vision pathology by the type of farsightedness in a person as D, then the gene for normal vision will be designated as d.

The mothers of both spouses with normal vision are dd, because homozygosity is a prerequisite for the phenotypic realization of normal vision. These women produced eggs exclusively of the d – type, and passed only the gene for normal vision to all their offspring.

Thus, a hyperopic man and a woman are heterozygous: Dd.