all the living and nonliving things in an area that interact with each other

Ecosystem

levels of organization

hierarchy

anything that constrains a population's size and slows or stops it from growing

limiting factors

the average number of individuals in a population per unit of area

population density

factors that affect population size and growth because of the number of species living there, like availability of food, parasitism, predation, disease, and migration

density dependent

factors that affect population size and growth that have nothing to do with how many species are living there, like natural disasters and human activity

density independent

something consumed by organisms that provides energy, and usually provides nutrients needed to sustain life

food

the liquid that fills the oceans, rivers, lakes, and ponds and falls from the sky as rain

water

a location or structure that gives protection

shelter

an area that is empty or open for use

space

all of the nonliving parts of an ecosystem, like air, water, and sunlight

abiotic factor

all of the living parts of an ecosystem, such as plants and animals

biotic factor

a group of different populations that live together and interact in an environment

community

a group of organisms that share similar characteristics and can mate with each other to produce offspring

species

the location in which an organism lives

habitat