A brown-eyed man married a blue-eyed woman. The child has blue eyes.

A brown-eyed man married a blue-eyed woman. The child has blue eyes. What are the genotypes of the father’s eye color? At the mother’s? The child has?

In a man, there are two possible genotype variants in which the color of his eyes will be brown: homo-KK, and heterozygous Kk. A woman has only one option – kk. The genotype of the child is the same as that of the mother. To find out the father’s genotype, let’s solve the problem with each option:
1.Р KK X kk
Г K X k
F1 Kk
In the first case, all possible children will have a brown color and a heterozygous genotype. It doesn’t fit the conditions.
2. P Kk X kk
Г K, k X k
F1 Kk, kk
In the second case, the appearance of children with both brown and blue colors is possible, in a ratio of 1: 1. The second option is suitable according to the condition of the problem, the genotype of the father is Kk.