A gray strand of hair in a person is a dominant feature, and its absence is recessive. determine the genotypes of parents

A gray strand of hair in a person is a dominant feature, and its absence is recessive. determine the genotypes of parents and children, if it is known that the mother has a gray strand, but the father does not.

Given:

A – the presence of a gray strand of hair;

a – the absence of a gray strand of hair;

To find:

P -?

F1 -?

Decision

Option 1:

P: AA x aa

G: Aa Aa Aa Aa

F1: Aa – 100% gray hair.

Option 2:

P: Aa x aa

G: Aa aa Aa aa

F1: Aa aa – 50% the presence of a gray strand of hair, 50% its absence.

Answer: the genotype of the mother is AA or Aa, the father is aa, the children are Aa or aa.