The presence of pigment in human hair dominates over albinism (lack of pigment).

The presence of pigment in human hair dominates over albinism (lack of pigment). Husband and wife are heterozygous for hair pigmentation, is it possible for them to have an albino child?

Let’s designate the gene that determines the presence of pigment in human hair as L, then the gene that determines the absence of pigment in the hair structure (albinism) will be designated as l.

Husband and wife, according to the condition of the problem, are heterozygous. They have genotypes Ll and produce two types of germ cells – L and l.

The offspring possible for a given married couple will be represented by the following options:

homozygous children with normal hair pigmentation (LL) – 25%;

heterozygous children with normal hair pigmentation (Ll) – 50%;

homozygous children who are albinos with hair deprived of pigment (ll) – 25%.

Answer: The probability of having an albino child in this family is 25%.