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Living and nonliving things in an environment, together with their interactions


Place where an organism lives and that provide the things that needs

biotic factor

a living part of an ecosystem

abiotic factor

a nonliving part of an ecosystem


process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches or other animal eats plant to obtain food.


a group of similar organisms that can mate with each other and produce fertile offsprin


Group of one species that live in the same area


populations of different species living in a defined area


the study of the relationship between organisms and their environment

population density

the number of individuals per unit area


An approximation of a number based on reasonable assumptions

birth rate

the number of births in a population in a certain amount of time

death rate

the number of deaths in a population in a certain amount of time


moving in to the population


leaving a population

limiting factor

an environmental factor that prevents a population from increasing

carrying capacity

largest number of individuals of a population that a environment can support

natural selection

the changes that make organism better suited to their environments.


the behaviors and physical characteristics that allow organisms to live successfully in their environments


how an organism makes a living (how survives in its environment)


the struggle between organisms to survive in a habitat with limited resources


interaction in which one organism kills and feeds on another organism


the organism that does the killing


an organism that is killed and eaten by another organism


a close relationship between two species that benefits at least one of the species


a relationship between two species in which both species benefit


symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed


A relationship between two organisms of different species where one benefits and the other is harmed


the organism that a parasite or virus lives in or on

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