In humans,freckles are dominant to no freckles,and unattached earlobes are dominant to attached earlobes.Two individuals who both have freckles and unattached earlobes have a child with no freckles and attached earlobes.What are the genotypes of the parents? (F = freckles; E = unattached earlobes)

Question

Quizplus · Accepted Answer

Since freckles are dominant and both parents have freckles, they must be either FF or Ff for the freckles gene. Similarly, since unattached earlobes are dominant and both parents have unattached earlobes, they must be either EE or Ee for the earlobe gene. When they have a child with no freckles and attached earlobes, this child must have the genotype ffEe. Therefore, both parents must be heterozygous for both genes (FfEe), which is option C.

In Humans,freckles Are Dominant to No Freckles,and Unattached Earlobes Are