| A | B |
| population | members of one kind of organism in an ecosystem |
| community | all the populations in an ecosystem |
| habitat | a living thing's place to live in an ecosystem |
| competition | the struggle among organisms for limited resources |
| abiotic | the nonliving factors of an ecosystem, such as rocks |
| ecosystem | all the living and nonliving things in an environment |
| biotic | the living factors of an ecosystem, such as plants |
| predators | animals that hunt other animals |
| prey | animals hunted by other animals |