A woman with brown eyes married a man with blue eyes. It is known that the wife’s father

A woman with brown eyes married a man with blue eyes. It is known that the wife’s father has brown eyes, and the mother’s blue. The man’s father had blue eyes, and the mother had brown. Determine the genotypes of all the persons mentioned. What are the phenotypes of the children from this marriage?

A – brown eye color, a  – blue.

Because the wife’s mother has blue eyes (aa), the wife inherited a recessive allele from her and is heterozygous (Aa). The wife’s father may have either the AA or Aa genotype.

The father’s mother is heterozygous because she gave him the allele and, therefore, her genotype is Aa. The man’s father has blue eyes (aa).

Crossing scheme:

Parents: Aa x aa,

Gametes: A, a x a,

Children: Aa (brown eyes), aa (blue eyes).

The probability of having a child with each of the phenotypes is 50%.