申論題

3. You are studying cells that normally respond to epidermal growth factor (EGF) by increasing their rate of cell division. You measure the cell division rate in the normal cells and the cells where a GTPase-activating protein (GAP) for Ras has been knocked down using small interfering RNA (siRNA). When the two types of cells are exposed to the same concentration of EGF, what differences in response to EGF do you expect? Explain your answer. (4%)