1. Quiz #3, Problem #1
Consider the pedigree below, the allele responsible for the trait (a) is recessive to the wild-type allele (A).
a. (2 pts) What is the genotype of individual I4?
b. (2 pts) What is the probability that individual III1 and III2 are a carriers of the trait?
2/3 x 2/3 = 4/9

2. Quiz #3, Problem #2
2. (2 pt) What is the probability of an A_bb phenotype, in the F2 generation, if the parental (P1) generation was AaBb x aaBb?
P1: Aa x aa & Bb x Bb
P(F1)
P(F2)
1/4 BB
= 1/4 AaBb
= 1/8 Aabb
3/16 A_bb
= 3/64
1/2 Aa
1/2 Bb
1/4 bb
3/4 A_bb
= 3/32
= 9/64
1/2 aa

3. Quiz #3, Problem #3
Each of the following pedigrees indicates the inheritance of a rare genetic disease. Match the mode(s) of transmission to the pedigree.
A: X-linked recessive C: X-linked dominant
B:, autosomal dominant D: autosomal recessive. B, C