Manipulated, controlled and responding variables activity

Here are the 3 problems that you were asked to determine the variables for:

Example: Do fish living in large aquariums grow to a larger size than fish raised in small aquariums?
Manipulated: size of tank
Controlled: size of fish at beginning of experiment, amount of food fed to them, amount of water, temperature of water
Responding: size of fish after the experiment

Questions for homework:
1. Does the gas consumption of a car change if there are more passengers in the vehicle?

2. How much does a baby's mass change each week during the first six months after birth?

3. Does the color of light given to a plant affect its rate of growth?