Plant Review

1. An element that makes up about 21% of Earth's atmosphere; a gas in Earth's atmosphere and in water that living organisms breathe.
3. A group of related objects that work together to perform a function.
6. The part of the atmosphere closest to Earth; the part of the atmosphere that organisms on Earth use for respiration (breathing).
7. energy That form of energy that animals can see directly.
8. Pores on the surface of a plant that allow gases to move into and out of the plant.
9. The part of a plant that grows away from the roots; supports leaves and flowers.

2. A substance such as a fat, a protein, or a carbohydrate that a living thing needs to survive.
3. To continue living or existing: An organism survives until it dies; a species survives until it becomes extinct.
4. A compound made of hydrogen and oxygen.
5. An organism that is made up of many cells, makes its own food through photosynthesis, and cannot move.