Todd has a see through glass tank with air, plants, and animals that eat those plants. He sealed the tank so no material can get into or out of it, but light can get in when the tank is not covered. The tank has been covered all night, and Todd measured the carbon in the air and found that it is increasing. How is carbon moving between the air and the living things in the tank? What is happening to the amount of carbon in living things? Explain your thinking as completely as possible.