| Term | Definition |
|---|---|
| abiotic | nonliving, not from a living organism |
| biogeochemical cycle | the movement of atoms and molecules from living organisms and the physical environment |
| biotic | a living organism or produced by a living organism. |
| carbon cycle | the movement of carbon from the nonliving environment into living things and back. |
| commensalism | a relationship between two organisms in which one organism benefits and the other is unaffected. |
| competition | ecological relationship in which two or more organisms depend on the same limited resource. |
| consumer | a organism that eats other organisms or organic matter. |
| decomposer | an organism that gets energy by breaking down the remains of dead organisms or animal wastes and consuming or absorbing the nutrients. |
| ecology | the study of the interactions of living organisms with one another and with their environment. |
| ecosystem | a community of organisms and their abiotic, or nonliving, environment. |
| energy pyramid | a triangular diagram that shows an ecosystem’s loss of energy, which results as energy passes through the ecosystem’s food chain. |
| food chain | the pathway of energy transfer through various stages as a result of the feeding patterns of a series of organisms. |
| food web | a diagram that shows the feeding relationships between organisms in an ecosystem. |
| limiting factor | an environmental factor that prevents an organism or population from reaching its full potential of size or activity. |
| mutualism | a relationship between two species in which both species benefit. |
| parasite | an organism that benefits from another species, the host, which is harmed. |
| parasitism | a relationship between two species in which one species, the parasite, benefits from the other species, the host, which is harmed. |
| predation | when a predator feeds on prey |
| predator | an organism that kills and eats all or part of another organism. |
| prey | an organism that is killed and eaten by another organism. |
| primary consumer | an animal that feeds on plants; a herbivore Any organism that consumes or feeds on autotrophs or decaying matter. |
| producer | an organism that can make its own food by using energy from its surroundings. |
| secondary consumer | a carnivore that feeds only on herbivores An organism that largely feeds on primary consumers |
| symbiosis | a relationship in which two different organisms live in close association with each other. |
| tertiary consumer | An organism that largely feeds on secondary and primary consumers. |
| trophic level | position in the food chain |
| water cycle | the natural sequence through which water passes into the atmosphere as water vapor, precipitates to earth in liquid or solid form, and ultimately returns to the atmosphere through evaporation. |
