Megan has a widow's peak (dominant trait) and attached earlobes (recessive trait). Megan's dad has a straight hairline and unattached earlobes. If Megan marries a man that is heterozygous for both traits, what is the probability that they will have a child with a widow's peak and attached earlobes?
A) 1/16
B) 3/8
C) 1/4
D) 1/2
E) 3/4

Question

Quizplus · Accepted Answer

Megan's genotype for widow's peak is Ww (since she has the dominant trait but her father has the recessive trait) and for attached earlobes is ee. Her husband's genotype is WwEe. The probability of a child having a widow's peak (W-) is 3/4, and the probability of having attached earlobes (ee) is 1/2. Multiplying these probabilities gives 3/8.

Megan Has a Widow's Peak (Dominant Trait) and Attached Earlobes