Question

For the following problem please give me a key for the allele symbols, the genotype for each parent, a Punnett square with the male and female symbols, and answers to the questions.
A certain trait, widow's peak (where the hairline on your forehead comes to a point), is a dominant trait. A woman with a widow's peak (she is heterozygous for the trait) has children with a man who ha a straight hairline. What are the chances that they will have a child with a widow's peak?

Answer 1

Key for allele symbols
- W = allele for widow's peak (dominant)
- w = allele for straight hairline (recessive)

Parent genotypes
- Mother (♀): heterozygous = Ww
- Father (♂): straight hairline = ww

Punnett square (female on left, male on top)
♂ w w
♀ W | Ww | Ww
w | ww | ww

Offspring genotypes and probabilities
- Ww: 2 out of 4 = 1/2 = 50% (phenotype: widow's peak)
- ww: 2 out of 4 = 1/2 = 50% (phenotype: straight hairline)

Answer
- The chance they will have a child with a widow's peak is 50%.