Based on genetic analysis of the yeast mutants, decide which component of the G protein normally transmits the mating signal to the downstream effector molecules (1 point, , , or ). Explain your answer (4 points, 3-4 sentences).

b. (6 points) Predict the proliferation and mating phenotypes in the absence and presence of the -factor pheromone of strains with the following mutant G protein  subunits:
i. An  subunit that can bind GTP but cannot hydrolyze it
ii. An  subunit that cannot bind to the activated pheromone receptor