Question

The presence of a widow's peak (pointed hairline on forehead) is inherited in a dominant manner. If two people who are heterozygous for widow's peak have children, what is the expected phenotypic ratio of their offspring

Answer 1

widow's peak children = 3/4

no widow's peak children = 1/4

Step-by-step explanation:

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

the expected phenotypic ratio of the offspring would be 3 to 1 widow's peak to no-widow's peak.