| A | B |
|---|
| abiotic | nonliving parts of the environment |
| autotroph | an organism that produces its own food; the source of energy for all other living things on earth |
| biodiversity | the variety of species in an area |
| biosphere | all of Earth's ecosystems, collectively; the biologically inhabited portions of Earth, including all of the water, land, and air in which organisms survive |
| biotic | the living parts of the environment |
| carnivore | an organism that survives by eating animals |
| carrying capacity | the largest population of any single species that an area can support |
| community | a combination of all the different populations that live and interact in the same environment |
| competition | the struggle between organisms for the same limited resources in a particular area |
| consumer | an organism that obtains its energy from producers |
| decomposer | an organism, generally a bacterium or fungus, that consumes (eats) dead organisms and organic waste |
| ecology | the study of how living things interact with one another and with their environment |
| ecological niche | the specific role played by an organism or a population of organisms in the ecosystem |
| ecological succession | the process by which an existing community is replaced by another community |
| ecosystem | all the living and nonliving things that interact in a specific area; a subdivision of the environment |
| energy pyramid | a diagram showing how food energy moves through the ecosystem |
| environment | every living and nonliving thing that surrounds an organism |
| food chain | a representation that identifies the specific feeding relationships among organisms |
| food web | a representation of many interconnected food chains that shows the feeding relationships among producers, consumers, and decomposers |
| habitat | the place where an animal or plant lives |
| herbivore | an organism that eats only plants |
| heterotroph | an organism that cannot make its own food; consumers |
| host | the organism in a parasitic relationship that provides a home and/or food for the parasite |
| limiting factors | any factor in the environment that limits the size of a population |
| parasite | an organism that survives by living and feeding on other organisms |
| population | all the individuals of a single species that live in a specific area |
| predator | an animal that hunts and kills other animals for food |
| prey | an animal that is hunted and killed by predators |
| producer | an organism that makes its own food from light energy and inorganic materials |
| scavenger | a carnivore that feeds on the bodies of dead organisms |
| biome | a climax community of plants and animals that covers a large geographic region |
| saprophytes | organismsms that feed on dead and decaying organisms, includes heterotrophic plants, bacteria, and fungi |
| omnivores | animals that feed on both plants and animals |
| climax community | final stable stage in an ecological succession |
| energy flow | the movement of energy through an ecosystem |
