Stomatas are pores on the plant leaf that control the flow of gases between the environment and the plant cells. this process the cells maintain a stable internal environment. which biology theme does this example represent?

Ascientist wants to determine the effect of a new type of gasoline. he fillsone car with normal gasoline and another identical car with the new gasoline.which is the control group? a. the new type of gasolineb. the car with the normal gasolinec. the car with the new gasolinethe amount of gasoline usedd. the amount of gasoline used