In humans the gene for the type of hairline an individual has is controlled by a single autosomal gene and the
allele for having a widow’s peak is dominant to the allele that causes the lack of a widow’s peak.
(a) Two heterozygous parents have a daughter that has a widow’s peak. What is the probability that their
second child will be a boy who lacks a widow’s peak?
(b) What is the probability that this couple will have three daughters in a row who all lack widows’peaks and
then a son who has a widow’s peak?