The pedigree shows the phenotypes for the hair color of individuals in a family over four generations. In this pedigree, light hair color is a recessive allele, and dark hair color is a dominant allele.
In the first generation of the pedigree, a dark-haired male is crossed with a light-haired female. This cross produces one dark-haired male, one light-haired female, and one dark-haired female in generation two. The dark-haired male in generation two crosses with a dark-haired female to produce three offspring, one dark-haired female, one light-haired male, and one labeled X in generation three. The dark-haired female from generation three crosses with a light-haired male to produce three offspring, one light-haired male, one dark-haired female, and one labeled W in generation four.
What is the probability that offspring W will have the dark hair phenotype?
a
25%
b
50%
c
75%
d
100%