[TheFrog]

Lets review: In 1772 Joseph Priestly discovered that if he put a mouse in a jar with a tightly sealed lid the mouse would soon die. However, if Priestly put a plant in the jar with the mouse and sealed it tightly the mouse lived. He reasoned that it was because the plant was breathing in CO2 and releasing O2. The mouse survived on the oxygen provided by the plant.

[whd23]

Lets review: In 1772 Joseph Priestly discovered that if he put a mouse in a jar with a tightly sealed lid the mouse would soon die. However, if Priestly put a plant in the jar with the mouse and sealed it tightly the mouse lived. He reasoned that it was because the plant was breathing in CO2 and releasing O2. The mouse survived on the oxygen provided by the plant.

Let's review: this only works when there is LIGHT. Hence the photo in photosynthesis. What gases do trees/plants release at night? (Hint: it isn't O2)