A widow's peak is a V-shaped area of the hairline in the center of the forehead. The allele for having a widow's peak is dominant to the allele for not having a widow's peak.
If two parents do not have widow's peaks, what is the probability that their child will have a widow's peak?
A.
25%
B.
0%
C.
50%
D.
75%
C. 50%
If both parents do not have widow's peaks, they must be homozygous recessive (ww). Since having a widow's peak is dominant (W), their child would need to inherit at least one dominant allele from one of the parents in order to have a widow's peak.
The possible genotypes of the parents are ww (both parents). The possible genotypes of their child could be Ww or ww. The likelihood of the child inheriting at least one dominant allele is 50%.