This problem examines possible biochemical explanations for variations of mendel’s 9: 3: 3: 1 ratio. except where indicated, compounds 1, 2, 3, and 4 have different colors, as do mixtures of these compounds. a and b are enzymes that catalyze the indicated steps of the pathway. alleles a and b specify functional enzymes a and b, respectively; these are completely dominant to alleles a and b, which do not specify any of the corresponding enzyme. if functional enzyme is present, assume that the compound to the left of the arrow is converted completely to the compound to the right of the arrow. for each pathway, what phenotypic ratios would you expect among the progeny of a dihybrid cross of the form aa bb × aa bb?