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?
*
75%
50%
25%
0
25%
The probability that their child will have a widow's peak is 0%.
To determine the probability that their child will have a widow's peak, we need to examine the genotypes of the parents.
If both parents do not have widow's peaks, it means that they both have the recessive allele for not having a widow's peak. Since the allele for having a widow's peak is dominant, it means that both parents must have the genotype "ww" (two copies of the recessive allele).
When two parents with the genotype "ww" have a child, the child will inherit one allele from each parent. Since both parents only have the recessive allele, the child can only inherit the recessive allele for not having a widow's peak (represented as "w"). Therefore, the genotype of the child will be "ww".
Since having a widow's peak is determined by the dominant allele, the child must have two copies of the recessive allele, and thus will not have a widow's peak.
Therefore, the probability that their child will have a widow's peak is 0%.