- In unicorns, the allele for silver hair, S, is dominant over the allele for rainbow hair, s. List all possible parental crosses that would give the following phenotypic proportions of offspring:
a. ½ silver hair, ½ rainbow hair
b. ¾ silver hair, ¼ rainbow hair
c. All rainbow hair
- In dragons, the genes that determine scale color and wing presence/absence are unlinked. The allele for black scales, B, is dominant over the allele for red scales, b, and the allele for winged, W, is dominant over the allele for wingless, w. Please give the expected genotypic and phenotypic proportions of the offspring of the following crosses. Please show your work.
a. BBWw x BbWw
b. Bbww x bbww
- A man, Rob, has disease X, a recessive, sex-linked disease. Rob’s daughter Zakiya doesn’t have the disease. Zakiya marries a man, Max, who also doesn’t have the disease. Zakiya and Max have a daughter, Beyonce, and a son, Kanye.
a. Draw a pedigree of the three generations, labeling each individual with his/her name and genotype (or possible genotypes).
b. What is the probability that Beyonce has disease X? Please show your work.
c. What is the probability that Kanye has disease X? Please show your work.
