| A | B |
| Abiotic | nonliving thing in an environment |
| Biotic | A living thing in an environment |
| Ecosystem | living and nonliving things in an environment all all of their interactions |
| Community | All of the populations in a ecosystem |
| Habitat | The place where an organism lives |
| Population | All the members of a single kind of organism that live in an ecosystem |
| carnivore | An animal that eats other animals |
| Consumer | An organism that cannot make its own food |
| Decomposer | An organism that breaks down wastes and the remains |
| Herbivore | An animal that eats mainly plants |
| Omnivore | An animal that eats both plants and animals |
| Producer | An organism, such as a plant, that makes its own food |
| Succession | The stages in building a new community where few living things exist, or were eariler |