1. (20 pts) The following pedigree shows the x-linked recessive inheritance of retinitis pigmentosum, a human condition that causes the progressive loss of night vision. Individual IV-2 has it especially bad. She is also afflicted with Turner's syndrome, a human condition characterized by females with only 45 chromosomes total but still contain the full complement of autosomes. Afflicted females are typically short, have a web of skin extending between the neck and shoulders, brown spots, and are sterile.

a) What is the genotype of individual IV-2 with respect to sex, use R and r as the allele designations (there is a hint in the description above)?

b) If individual IV-6 marries IV-7 what is the probability that they will have a child with retinitus pigmentosum and what would be that child's sex?

c) Assuming that individual IV-7 was a carrier, what is the probability of them having five children, two of which have retinitis pigmentosum? (Note: you do not have to solve the equation)

d) How does the answer to (c) change if we do not assume that individual IV-7 is a carrier (hint: see answer for (b))?

e) What is the probability of them having all affected girls?