Andrey always wanted to have a gray strand over his forehead, like dad and mom. But he has no strand, like both grandmothers (recessive trait (a)). Determine the genotypes of family members for the indicated trait.
Because Andrei lacks a gray strand – a recessive trait, which means the genotype is aa, but the mother and father have it (grandmothers do not have -aa on both lines), which means the parents are heterozygous (Aa) by the trait.
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