In humans, dark hair (B) is dominant over blondness (b), and color blindness (c) is a sex-linked recessive trait. A women has a blond brother, a blond mother, and a dark-haired father. Her brother and her parents have normal vision. She bears the following three children by her blond, normal-visioned husband:
a dark-haired son with normal vision,
a dark-haired daughter with normal vision, and
a dark-haired color-blind son
i) Make a pedigree of the entire family showing the probable genotypes of all individuals.
ii) What is the probability that her next (fourth) child will be a color-blind boy?
iii) If her fourth child is a boy, what is the probability that he will have dark hair?
iv) What is the chance that her next four children will all be girls?