The blue-eyed father and the brown-eyed mother have brown-eyed and blue-eyed children.

The blue-eyed father and the brown-eyed mother have brown-eyed and blue-eyed children. Determine the genotypes of parents and children

The gene for blue eyes, as you know, is recessive, let us designate it as, then the gene that determines the development of brown eyes will be B. Blue-eyed father – cc, produces the same type of spermatozoa c. To be the father of brown-eyed children, he must marry a woman capable of passing on the gene for the dominant trait, B.

Blue-eyed children, like their father, bb. Their brown-eyed mother must be able to produce eggs containing the gene for this recessive trait. Consequently, the mother is heterozygous – Bb, and produces both types of eggs – b and B. Children with blue eyes in the offspring of a blue-eyed man (bb) and a brown-eyed woman – heterozygote (Bb) will be 50%.

Brown-eyed children will make up 50% of the offspring and have a heterozygous Bb genotype.