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