Feather color in parakeets is produced by the blending of pigments from two biosynthetic pathways shown below. Four independently assorting genes (A, B, C, and D) produce enzymes that catalyze separate steps of the pathways. For the questions below, use an uppercase letter to indicate a dominant allele producing full enzymatic activity and a lowercase letter to indicate a recessive allele producing no functional enzyme. Feather colors produced by mixing pigments are green (yellow + blue) and purple (red + blue). Red, yellow, and blue feathers result from the production of one colored pigment, and white results from the absence of pigment production.
If a pure-breeding blue strain of parakeet (aa BB CC DD) is crossed to one that is pure-breeding purple, predict the genotype(s) and phenotype(s) of the F1. Show your work
