Question

The allele for a widows peak hairline is recessive. Mulan has a widows peak. Both of her parents have widows peaks. What is the probability for Mulan to have a widows peak? Create a Punnett square to prove your answer

Answer 1

Assuming that the allele for a widows peak is represented by "w", and the allele for a straight hairline is represented by "W", we can represent Mulan's parents as WW (father) and Ww (mother), where the lowercase "w" represents the widows peak allele, and the uppercase "W" represents the straight hairline allele.

To create a Punnett square to determine the probability of Mulan having a widows peak, we can represent Mulan as the offspring of this cross:

| W | w

--|------|---

W | WW | Ww

--|-------|---

W | WW | Ww

Each box in the Punnett square represents a possible combination of alleles that Mulan could inherit from her parents. We can see that there are four possible outcomes, each with a 50% chance of occurring.

Mulan can inherit the widows peak allele from her mother and the straight hairline allele from her father, resulting in the genotype Ww, but with a widows peak phenotype. Therefore, the probability of Mulan having a widows peak is 1/2 or 50%.

To summarize, the Punnett square shows that there is a 50% chance for Mulan to inherit the widows peak allele from her mother and a 50% chance for her to inherit the straight hairline allele from her father. Therefore, the probability of Mulan having a widows peak is 50%.