| A | B |
| abiotic | The nonliving parts of an ecosystem. |
| biotic | The living parts of an ecosystem. |
| organism | A living thing. |
| population | All the members of one species in a particular area. |
| community | All the different populations that living together in an area. |
| ecosystem | All the living and nonliving things that interact in a particular area. |
| Abiotic parts of an ecosystem | Water, sunlight, rocks, temperature |
| Biotic parts of an ecosystem | Animal, plants, fungi, protists |