Question

The gene for hairline shape has two alleles: widow's peak (W) and straight hairline (w). What is the percent probability that one child of a mother with the genotype Ww and a father with a straight hairline will have the genotype Ww? Use a Punnett Square to figure out the likelihood

Answer 1

Probability of having a child with genotype Ww is 50%.

Step-by-step explanation:

This question involves a single gene coding for hairline shape in humans. The allele for widow's peak hairline (W) is dominant over the allele for straight hairline (w). This means that allele W will mask the phenotypic expression of allele w in a heterozygous state.

In a cross between a mother with genotype, Ww and father with genotype, ww, the following gametes will be produced by each parent:

Mother (Ww)- W and w

Father (ww)- w and w

Using these gametes in a punnet square (see attached image), four possible offsprings will be produced with genotypes: Ww, Ww, ww and ww.

Ww(2) : ww(2) or Ww(1) : ww(1)

Hence, 1 out of 2 children produced by the parents will have a genotype Ww, i.e. 1/2. Therefore, the percentage probability is 1/2 × 100= 50%.