Q1. A cross between two inbred plants that had mean seed weights of 20 and 40 grams, respectively, produced an F1 generation with seeds weighing an average of 30 grams each. An F1 x F1 cross produced 1000 plants: 3 had seeds weighing 20 grams, 5 had seeds weighing 40 grams, and the others produced seeds with weights varying between these extremes. How many gene pairs are involved in determining seed weight differences in these plants?

Q2. Cancer patients undergoing chemotherapy are normally more susceptible to infections. However, a patient receiving an antitumor drug that inhibited cell division was resistant to salmonella. Provide a possible mechanism for the resistance.