Essentials of Genetics 9th Edition by Michael Palladino William Klug, Michael Cummings, Charlotte Spencer

Exercise 9

Given the inheritance pattern of coat color in rats described in Problem 1, predict the genotype and phenotype of the parents that produced the following F 1 offspring: (a) 9/16 gray: 3/16 yellow: 3/16 black: 1/16 cream; (b) 9/16 gray: 3/16 yellow: 4/16 albino; (c) 27/64 gray: 16/64 albino: 9/64 yellow: 9/64 black: 3/64 cream.
Problem 1
The following genotypes of two independently assorting autosomal genes determine coat color in rats:

A third gene pair on a separate autosome determines whether any color will be produced. The CC and Cc genotypes allow color according to the expression of the A and B alleles. However, the cc genotype results in albino rats regardless of the A and B alleles present. Determine the F 1 phenotypic ratio of the following crosses: (a) AAbbCC × aaBBcc ; (b) AaBBcc × AABbcc ; (c) AaBbCc × AaBbcc.