| A | B |
|---|
| ecosystem | all living & nonliving things in an area |
| ecology | study of living things interacting in their environment |
| abiotic factor | nonliving part of ecosystem |
| biotic factor | living part of an ecosystem |
| populations | all members of a species in an area at a time |
| community | all populations living in an area |
| habitat | the area in which an organism lives |
| niche | the role an organism has in its ecosystem |
| organism | living things |
| producers | organisms that produce oxygen or food that animals need |
| consumers | organisms that eat plants/animals that eat plants |
| decomposers | organisms that break down dead plants/animals |
| topsoil | top layer of soil |
| humus | partly decayed plant matter |
