Definitions - Interactions in the Environment

These are the current definitions that you should be studying.  Updated November 9th.

This list is now complete for this unit.


Biotic The living components of an ecosystem.
Abiotic The non-living components of an ecosystem. Example: Wind, Sun, Water, etc



A single living thing.
Population A group of organisms of the same species in an ecosystem.
Community A group of different populations interacting in an ecosystem.
Ecosystem All the organisms living in a particular area, as well as all the nonliving, physical components of the environment with which they interact.
Biome A region of land with characteristic climate, soil and organisms.
Weather Describes the conditions of the atmosphere in a certain area for a short period of time. Weather changes constantly.
Climate Describes the average weather that an area has over a long period of time. Climate does not generally change (can change over years).
Biosphere The areas on and around Earth that can sustain life.
Atmosphere The air, in the biosphere, that surrounds Earth.
Lithosphere The solid mineral material, in the biosphere, on Earth.
Hydrosphere The water, in the biosphere, on Earth.
Niche The role of an organism in an ecosystem.
Producer Plants that use energy from the sun to make nutrients they need to survive.
Consumer Organisms that eat food made by producers. (Primary Consumer eats plants, Secondary Consumer eats meat)
Herbivore An animal that eats only plant material.
Carnivore An animal that eats only other animals.
Omnivore An animal that eats other animals and plant material.
Predator An organism that catches and eats other organisms of a different species.
Prey An organism that is caught and eaten by another organism of a different species.
Scavenger An organism that eats dead or decaying plant or animal matter.
Decomposer Organisms that break down the cells of dead or waste materials and absorb their nutrients.
Food Chain A sequence of feeding relationships among living organisms, as they pass on food energy.
Energy Flow The movement of energy, which originally comes from the sun, from one organism to another.
Food Web The network of feeding relationships among organisms.
Symbiosis An interaction between two organisms of different species living in close proximity that lasts over time.
Parasitism A symbiotic relationship in which one of the partners is harmed and the other benefits.
Mutualism A symbiotic relationship in which both partners benefit.
Commensalism A symbiotic relationship in which one partner benefits and the other is indifferent.
Energy Pyramid A pyramid showing the number of organisms at each level of a food chain.
Succession The process by which new species gradually replace old species in an ecosystem.
Secondary Succession When succession occurs with already existing soil.
Sustainability The ability to sustain something - to keep in healthy and continue in the same manner.