Current science

Ecology

The study of ho organisms interact with their environment

Organisms

get food, water, and shelter, and other things it needs to live, grow, and reproduce from their environments

Habitat

an environment that provides things a specific organism needs to live, grow, and reproduce

biotic factors

the living or once living parts of a habitat that interact with an organism

Abiotic factors

the nonliving parts of a habitat

A species

a group of organisms that produce offspring that can mate and reproduce

Population

All the organisms belonging to one species in an area

Community

all of the different living things or populations that live together

Ecosystem

All the living and nonliving things in an environment

Biosphere

All of the living things on earth

The levels of an ecosystem from largest to smallest

Ecosystem, community, population, and organism

The levels of an ecosystem from smallest to largest

organism, population, community, ecosystem

Populations changing size

Mainly by death and birth

Birth rate

The number of births per 1000 individuals for a given time

Birth rate > death rate

population size will increase

Death rate> birth rate

population size will decrease

Birth rate = death rate

population size will remain constant

Immigration

When new members move into a population

Emigration

When members leave the population

Reasons why individual immigrate/emigrate

Food, water, living space, climate

Population density

P=N/U

Limiting factor

an environmental factor that causes a population to stop growing or decrease in size

Carrying capacity

the largest possible population that an area can support