| A | B |
|---|
| adaptation | inherited characteristic that increases an organism's chance of survival |
| biomass | any organic material that has been produced in an ecosystem |
| biota | all plant and animal life of a particular region, biotic factors |
| birth rate | the number of births occurring in a period of time |
| carrying capacity | largest number of individuals of a population that a environment can support |
| commensalism | the relation between two different kinds of organisms when one receives benefits from the other without damaging it |
| community | a group of interdependent organisms inhabiting the same region and interacting with each other |
| consumer | organism that relies on other organisms for its energy and food supply; also called a heterotroph |
| death rate | the ratio of deaths in an area to the population of that area |
| decomposer | organism that breaks don an obtains energy from dead organic matter |
| ecology | the branch of biology concerned with relations between organisms and their environment |
| ecosystem | all the biotic and abiotic components of an environment |
| emigration | the movement of organisms out of a population |
| endangered species | a species whose numbers are so small that the species is at risk of extinction |
| estimate | an approcimation of a number based on reasonable assumptions |
| extinction | the complete elimination of a species from the earth. |
| food chain | a series of steps in which organisms transfer energy by eating and being eaten |
| food web | a community of organisms where there are several interrelated food chains |
| immigration | moving into a population |
| interdependence | mutually dependent; depending on each other |
| limiting factor | an environmental factor that prevents a population from increasing |
| mutualism | the relation between two different species of organisms that are interdependent |
| niche | organisms role or job in its habitat |
| parasitism | symbiotic relationship in which one organism lives in or on another organism and consequently harms it |
| population | all members of one species in a particular area |
| population density | number of individuals per unit area |
| producer | organism that makes its own food (autotroph) and produces organic molecules that serve as food for other organisms in its ecostystem |
| society | group of closely related animals of the same species that work together for the benefit of the group |
| species | group of similar organisms that can breed and produce fertile offspring |
| symbiosis | the relation between two different species of organisms that are interdependent |
