Feather color in parakeets is produced by the blending of pigments produced from two biosynthetic ...

Feather color in parakeets is produced by the blending of pigments produced 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 production of one colored pigment, and white results from absence of pigment production.
Part A
What is the genotype of a pure-breeding green parakeet strain?
Express your answer as combination of allelic symbols. Example: AaBBccDd.


Part B
What is the genotype of a pure-breeding yellow strain of parakeet?
Check all that apply.

    AAbbccdd
    aaBBccdd
    AAbbCCdd
    AABBCCDD
    aaBBCCdd
    AABBccdd<<
    AABBccDD<<
    AABBCCdd<<

Part C
If a pure-breeding blue strain of parakeet aaBBCCDD is crossed to one that is pure-breeding purple, predict the possible genotype(s) of the F1.
Check all that apply.

    AabbCCDD
    AaBbCCDD
    AABBCCDD
    AaBBCCDD
    aaBbCCDD
    AaBbCCdd
    AaBbccDD
    aabbCCDD


Part D
If a pure-breeding blue strain of parakeet aaBBCCDD is crossed to one that is pure-breeding purple, predict the possible phenotype(s) of the F1.
Check all that apply.
Check all that apply.
    purple
    yellow
    blue
    white
    green
    red