Question: (a) A certain bacteria requires a green compound to survive. The biochemical pathway that convert…

(a) A certain bacteria requires a green compound to survive. The
biochemical pathway that converts minimal medium into the green
compound contains at least 2 precursors that are metabolized by
Enzymes A and B as shown below. One precursor is colored red and
the other is blue, but the order is unknown.

You are given 4 clonal colonies of this bacteria. Each colony
contains the same set of mutations (if any).

Fill in the blanks above to indicate the order of the
biochemical pathway. Circle + or – below to indicate whether each
gene is wild-type (+) or mutant (-) in each bacterial colony. (Gene
A encodes Enzyme A…)

(b) Two haploid yeast mutants, C1 and C2, are auxotrophic for
arginine. When C1 is crossed with C2, the diploid progeny cannot
grow on minimal medium.

Which of the following situations is consistent with the
behavior observed above? Circle ALL that apply. (A, B, C, and D are
all different genes)