In humans, a widow\'s peak is caused by a dominant allele W, and a continuous ha
ID: 217441 • Letter: I
Question
In humans, a widow's peak is caused by a dominant allele W, and a continuous hairline is caused by a recessive allele w. Short fingers are caused by a dominant allele S, and long fingers are caused by a recessive allele s. Suppose a woman with a continuous hairline and short fingers and a man with a widow's peak and long fingers have three children. One child has short fingers and a widow's peak, one has long fingers and a widow's peak, and one has long fingers and a continuous hairline. What are the genotypes of the parents?
Explanation / Answer
What are the genotypes of the parents?
Female wwSs, male Wwss
Because they have a kid with long fingers, hence the mother should have one dominant (S) and one recessive (s) allele in order for the child to have fingers (s from the mother and s from the father). The mother is supposed to have a continuous hairline, which is ww. On the other hand, other child with continuous hairline indicates that the father has one dominant (W) and one recessive allele (w).