4b. An additional gene, called W, is found that affects the synthesis of enzymes I and 2. Mutant d has a recessive mutation in gene W. enzyme activity genotype without fictamine with fictamine 2 strain W X Y Z 2 wild-type + + + + + mutant a + + + + mutant b + + + mutant c + + + + + + + mutant d + + + + + Once again, justify each answer in one sentence. i) is gene W most likely a positive or a negative regulator? ii) Is the activity of W activated or inactivated by the presence of fictamine? iii) Two of the regulatory networks (1-4) shown below are consistent with the results presented above. Which are they? (- indicates a stimulatory or positive interaction; indicates a negative interaction). N Y 7, -X W 4 W X Z W X Y Z W