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a characteristic that helps an organism survive in its habitat

behavioral adaptation

special behaviors that help organisms adapt to changes in their environment


describes the great variety of life-forms on earth or within a habitat


a meat-eating animal


a symbiotic relationship in which one organism benefits while the other is not affected


all the different populations that live within a habitat


an organism that obtains nutrients by eating other organisms


a state in which an organism is inactive while it awaits more favorable conditions in its environment

ecological succession

the natural process by which one community of living things is replaced by another community in an orderly, predictable sequence, until a stable climax community appears


the living members of a community, plus the nonliving elements of their environment

endangered species

a species that is in danger of extinction


species that no longer exist

food chain

a sequence of organisms through which nutrients are passed along in an ecosystem

food web

a number of interconnected food chains


the remains or traces of an ancient organism


the particular environment in which an organism lives


a plant-eating animal


a sleeplike state of reduced body activity that some animals enter to survive the winter


moving from one environment to another where conditions are more favorable


a symbiotic relationship in which both organisms benefit


a consumer that can eat both plants and other animals


a symbiotic relationship in which one organism benefits while the other is harmed

physical adaptation

a physical characteristic that enables an organism to survive under a given set of conditions


all the members of a particular species that live within a habitat


an organism that makes its own food; most producers are green plants


the reaction of a living thing to a change in its environment


a change in the environment that causes an organism to react in some way


a relationship in which two or more different organisms live in close association with one another; that is, when one organism lives on or inside another one

Major Concept

Living things and the nonliving things in their surroundings make up an ecosystem. Adaptations allow an organism to survive in a particular ecosystem.

Major Concept

Green plants use sunlight to make their own food. They are called producers. Animals depend on other organisms for food. They are called consumers. All organisms get their energy directly or indirectly from the sun.

Major Concept

Decomposers are organisms that break down the remains of dead plants and animals. Decomposers return nutrients to the environment.

Major Concept

Producers, consumers and decomposers may be linked in a food chain. Disturbing any part of a food chain affects other organisms the food chain.

Major Concept

There is a constant exchange of materials between an organism and its environment; these materials include food, water, oxygen and wastes.

Major Concept

Ecological succession is the natural process by which one community is replaced by another community in an orderly, predictable way.

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