In humans, brown eye color (A) dominates over blue, normal skin pigmentation (B) over albinism.

In humans, brown eye color (A) dominates over blue, normal skin pigmentation (B) over albinism. The genes for both traits are found on different chromosomes. A brown-eyed albino man whose mother was blue-eyed married a blue-eyed albino woman. Determine the genotypes of the parents, genotypes and phenotypes of the offspring.

According to the notation system introduced in the problem statement, we will write down the genotypes of the parents.

A blue-eyed albino woman would be aabb because homozygosity is the only possible chance for the trait to be phenotypically realized. Her body produces eggs ab.

The mother of a brown-eyed man, like the woman described, is homozygous for eye color – aa, and only the blue-eyed gene can be passed on to her son. Considering that the man has brown eyes, he is heterozygous for eye color – Aabb. The sperm produced by his body are Ab and ab.

Probable offspring of such a marriage:

brown-eyed albinos (Aabb) – 50%;

blue-eyed albinos (aabb) – 50%.