| Term | Definition |
| ecosystem | all the biotic and abiotic factors in a given area interacting with each other |
| community | group of populations of different species living in the same area, interacting |
| population | group of organism of the same species living together in the same area |
| individual | one organism of one species |
| habitat | place in which an organism lives |
| niche | an organism's role in life |
| ecology | the study of the relationship and interactions of living things with their environment |
| food chain | an arrangement of the organisms in a community according to the order of predation |
| food web | interacting food chains in an ecological community |
| producer (autotroph) | organism that makes it own food (ex. green plants) |
| comsumer (heterotroph) | organisms that cannot make its own food |
| carnivore | organism that eats only meat |
| herbivore | organism that eats only plants |
| omnivore | organism that eats both plants and meat |
| predator | organism that hunts, kills, and eats other organisms |
| prey | organism hunted by the predator |
| scavenger | organism that hunts and feeds on dead animals |
| decomposer | organism that breaks down dead organisms into simpler substances |
| symbiosis | a close relationship between 2 organisms in which 1 of the organisms lives near, on or even inside another organism and at least one of the organism's benefit |
| types of symbiosis | commensalism, mutualism, parasitism |
| commensalism | one organism benefits and the other is not harmed |
| mutualism | both organisms benefit |
| parasitism | one organism benefits and the other is not harmed |
| biotic factor | any living thing |
| abiotic factor | any non-living thing |
| environment | everything that surrounds a living thing including biotic and abiotic factors |