Explanation:

Person B is blonde, because they are shaded in. They are thus homozygous recessive (hh).

Persons C through F must have at least dominant allele (H). Without more information, this would make them HH or Hh.

Person B can only provide the h alleles to its eggs, so persons C-F must be heterozygous (Hh).

Without more information, Person A who is dominant must be HH or Hh.

[Return to Pedigree Sample Problem #1]

Slichter