For this week’s assignment, you will solve the following genetics problems in the space provided on this assignment. You should hand-write your solutions to these problems. This assignment is worth 10 points, but you may earn up to 12 points on it. I will not accept late assignments.
1. (3 pts) Achondroplasia is a short-limbed dwarfism that is inherited as an autosomal dominant disease. The mutant allele that causes this form of dwarfism (D) is dominant to the normal allele at this location (d). Tom and Vonna both have achondroplasia (but each of them has an average-sized parent). Tom and Vonna have 3 children, 2 of whom have achondroplasia. Tom and Vonna also had 3 stillborn children and 1 child die just after birth.
a. What are the likely genotypes of Tom and Vonna with respect to the achondroplasia locus?
b. If Tom and Vonna have another child, what is the probability that this child will be healthy?
c. If Tom and Vonna have 2 more children, what is the probability that both of them will be healthy?
d. Consider the 4 children who passed away. What do you think the genotypes of these children were with respect to achondroplasia? (You may have to go online to research this question). Why?
2. (3 pts) Examine the following pedigree. Males are represented by squares and females by circles. Individuals with the trait (of interest) are filled in.
a. Is this trait inherited as an autosomal dominant or an autosomal recessive disorder? Explain how you can be sure.
b. What are the genotypes of the following individuals? Use your own symbols when generating these genotypes. Some genotypes may not be fully resolved.
Individual I2: Individual II2: Individual I3: Individual II3:
c. If individuals II3 and II4 have another child, what is the probability that their child will inherit this trait? 3. (2 pts) In summer squash, fruit color and shape are inherited as single gene, autosomal traits. White fruit color (W) is dominant over yellow fruit color (w) and disk-shaped fruit (D) is dominant over sphere-shaped fruit (d).
a. Suppose two squash plants with the following genotypes are mated: WWDd x wwDd.
