Biology: Concepts and Investigations 2nd Edition by Mariëlle Hoefnagels

Exercise 34

One of the classic experiments in photosynthesis occurred in 1771, when Joseph Priestley found that if he placed a mouse in an enclosed container with a lit candle, the mouse would die. But if he also added a plant to the container, the mouse could live. Priestley concluded that plants "purify" air, allowing animals to breathe. What is the biological basis for this observation?