Mr. and mrs. anderson both have tightly curled hair. (the hair form gene shows incomplete dominance. there are two alleles, curly and straight. the heterozygote has wavy hair.) the andersons have a child with wavy hair. mr. anderson accuses mrs. anderson of being unfaithful to him. is he necessarily justified? why or why not?

Mr. Anderson is justified.

Explanation:

First of all you need to understand that the genes responsible for the hair, establish a relationship of incomplete dominance and not, necessarily complete dominance, when heterozygosis occurs. That is, curly hair has the "CC" alleles, straight hair has the "cc" alleles, however, wavy hair has an incomplete and not complete dominance, with the "Cc" genotypes.

In the question above, we saw that you and Mrs. Anderson have very curly hair, which means that both have "CC" alleles. At an intersection where the two parents are homozygous dominant, all offspring are homozygous dominant, so the son of Mr. and Mrs. Anderson should have the "CC" alleles and have curly hair, however, this child has wavy hair, which means that he has the "Cc" alleles, indicating that Mrs. Anderson was unfaithful and that the child's real father has straight hair.