| A | B |
|---|
| ecosystem | All the plants and animals of an area and the physical place in which they live. |
| abiotic factor | A nonliving part of an ecosystem. |
| humus | A dark-colored layer of soil formed by decaying plants and animals. |
| biotic factor | A living part of an ecosystem. |
| species | A group of organisms that share similar characteristics and can reproduce among themselves producing fertile offspring. |
| population | The number of individuals of one species that occupy the same area. |
| community | All the species that occupy an area. |
| limiting factor | An environmental factor that limits the growth of a population of organisms in an ecosystem. |
| climate | Long-term, average weather patterns of an area. |
| biome | A zone of major ecological communities on Earth. |
| habitat | The place an organism lives. |
| niche | A unique ecological role of a species. |
| latitude | The distance in degrees north and south of the equator. |
