Heterozygous, brown-eyed woman, married to a brown-eyed man, blue-eyed children, what is the man’s genotype?

Answer: heterozygous.
Given:
A – brown eyes
a – blue eyes
Aa – heterozygous mother
aa – child
Find out:А? – father’s zygosity
Solution: It is worth considering an important fact that if the father were homozygous (AA), then all the offspring would be with brown eyes.
Therefore, it is logical to assume that the father is heterozygous (Aa), like the mother (Aa). The offspring may well be blue-eyed (aa).