Widow's peak is a dominant trait. Assuming that the gene that controls the trait is represented by the allele A, the alternate form (no-widow's peak) would be a.
If two people who are heterozygous have children:
Aa x Aa
AA Aa Aa aa
widow's peak = 3/4
no widow's peak = 1/4
<em>the expected phenotypic ratio of the offspring would be 3 to 1 widow's peak to no-widow's peak.</em>
