In humans, the allele for brown eyes (B) is dominant over the allele for blue (b). A couple, one of whom has brown eyes and the other blue, have four children, all with brown eyes. Is this proof that the brown-eyed parent is homozygous dominant? Why?
No because if the parent is heterozygous (Bb) then it’s still possible for all four children to inherit the same dominant gene. Unlikely, but possible.
