In humans,"unattached" earlobes are dominant over "attached" earlobes.Widow's-peak hairline is dominant over non-widow's-peak hairline.Use E and e for the earlobe phenotype alleles and W and w for the hairline phenotype alleles.A woman with unattached earlobes and a widow's peak and a man with attached earlobes and a widow's peak have a child.The child has attached earlobes and a non-widow's-peak hairline.What are the genotypes of the parents?

Question

Quizplus · Accepted Answer

The woman must have at least one dominant allele for each trait (E and W) but must carry a recessive allele for earlobes (e) since the child has attached earlobes (ee). The man must have attached earlobes (ee) and at least one dominant allele for the widow's peak (W), but also carries a recessive allele for the hairline (w) since the child has a non-widow's-peak hairline (ww). Therefore, the woman's genotype is EeWw and the man's is eeWw.

In Humans,"unattached" Earlobes Are Dominant Over "Attached" Earlobes