2. The Biosphere the thin layer of the earth that supports life.
If the earth was the size of an apple, the biosphere would be the thickness of its skin.

3. An organism has all the characteristics of life.

4. A population is group of interacting and interbreeding organisms.
Members of a population must be all the same species.

5. A community is a group of interacting populations.

6. A community includes all the living things (biotic factors) in one place.
It contains no abiotic factors.

7. An ecosystem is a community plus its non-living (abiotic) environment.
Abiotic Factor
Biotic Factor