Term | Definition |
community | Assemblage of species interacting with one another within the same environment. |
species richness | Number of species in a community. |
species diversity | Variety of species that make up a community. |
island biogeography model | Proposes that the biodiversity on an island is dependent on its distance from the mainland, with islands located a greater distance having a lower level of diversity. |
habitat | Place where an organism lives and is able to survive and reproduce. |
ecological niche | Role an organism plays in its community, including its habitat and its interactions with other organisms. |
Abiotic Factors | Nonliving examples: Climate, Habitat |
Biotic Factors | Living examples: competitors, parasites, and predators |
competitive exclusion principle | Theory that no two species can occupy the same niche in the same place and at the same time. |
resource partitioning | Mechanism that increases the number of niches by apportioning the supply of a resource, such as food or living space, between species. |
character displacement | Tendency for character-istics to be more divergent when similar species belong to the same community than when they are isolated from one another. |
predation | Interaction in which one organism (the predator) uses another (the prey) as a food source. |
predator | Organism that practices predation. |
prey | Organism that provides nourishment for a predator. |
camouflage | Process of hiding from predators in which an organism’s behavior, form, and pattern of coloration allow it to blend into the background and prevent detection. |
mimicry | Superficial resemblance of two or more species; a survival mechanism that avoids predation by appearing to be noxious. |
symbiosis | Relationship that occurs when two different species live together in a unique way; it may be beneficial, neutral, or detrimental to one or both species. |
parasitism | Symbiotic relationship in which one species (the parasite benefits in terms of growth and reproduction to the detriment of the other species (the host). |
parasite | Species that is dependent on a host species for survival, usually to the detriment of the host species. |
host | Organism that provides nourishment and/or shelter for a parasite. |
commensalism | Symbiotic relationship in which one species is benefited, and the other is neither harmed nor benefited. |
mutualism | Symbiotic relationship in which both species benefit in terms of growth and reproduction. |
coevolution | Mutual evolution in which two species exert selective pressures on the other species. |
ecosystem | Biological community together with the associated abiotic environment; characterized by a flow of energy and a cycling of inorganic nutrients. |
autotroph | Organism that can capture energy and synthesize organic molecules from inorganic nutrients. |
producer | Photosynthetic organism at the start of a grazing food chain that makes its own food—e.g., green plants on land and algae in water. |
heterotroph | Organism that cannot synthesize needed organic compounds from inorganic substances and therefore must take in organic food |
consumer | Organism that feeds on another organism in a food chain generally; primary consumers eat plants, and secondary consumers eat animals. |
herbivore | Primary consumer in a grazing food chain; a plant eater. |
carnivore | Consumer in a food chain that eats other animals. |
omnivore | Organism in a food chain that feeds on both plants and animals. |
detritivore | Any organism that obtains most of its nutrients from the detritus in an ecosystem. |
decomposer | Organism, usually a bacterium or fungus, that breaks down organic matter into inorganic nutrients that can be recycled in the environment. |
food web | In ecosystems, a complex pattern of interlocking and crisscrossing food chains. |
food chain | The order in which one population feeds on another in an ecosystem, thereby showing the flow of energy from a detritivore (detrital food chain) or a producer (grazing food chain) to the final consumer. |
trophic level | Feeding level of one or more populations in a food web |
ecological pyramid | Visual depiction of the biomass, number of organisms, or energy content of various trophic levels in a food web—from the producer to the final consumer populations. |
Fundamental Niche | All conditions under which organisms can survive. |
Realized Niche | Set of conditions under which it exists in nature (predators, competition,etc) |
Batesian mimicry | Mimicry lacks defense of the orgainsm it resembles. |
Mullrian mimicry | Mimic shares a protective defense with other species. |