Essential Genetics 6th Edition by Daniel Hartl

Exercise 18

Albinism refers to a total lack of skin pigment due to a rare recessive gene. What is the probability that a mating produces an albino child if:
(a) Both parents are normally pigmented, as are the grandparents, but each parent has an albino sibling.
(b) The father is albino and the mother has no family history of albinism.
(c) The mother is albino and the father has normal pigmentation although his father was albino.