The ALDH gene has two primary alleles. The dominant D allele results in production of nonfunctional ALDH enzyme. This results in a build-up of acetaldehyde and a flush reaction when an individual consumes alcohol. The recessive d allele results in production of a functional ALDH enzyme and lack of a flush reaction. First, we are interested in the presence or absence of the flush reaction phenotype.

1. Jasmine and her mother both get a flush reaction when they drink alcohol. Jasmine’s father does not. Jasmine’s husband, Jake, does not get a flush reaction, but his mother and father both do.

a. Draw a pedigree of Jasmine, Jake, and their parents. Label each individual with his/her genotype.

b. What genotypic ratio is expected among Jasmine and Jake’s kids? Show your work with a Punnett square.

c. What proportion of Jasmine and Jake’s kids are expected to exhibit the flush reaction? Explain.