Like this study set? Create a free account to save it.

Sign up for an account

Already have a Quizlet account? .

Create an account


features of the environment that are alive or were once alive


nonliving, physical features of the environment, including air, water, sunlight, soil, temperature, and climate


air surrounding Earth; is made up of gases, including 78 % nitrogen, 21 % oxygen, and 0.03% carbon dioxide


mixture of mineral and rock particles, the remains of dead organisms, air, and water that forms the topmost layer of Earth's crust and supports plant growth.


average weather conditions of an area over time, including wind, temperature, and rainfall or other types of precipitation such as snow or sleet.


process that takes place when a liquid changes to a gas


process that takes place when a gas changes to a liquid

water cycle

model describing how water moves from Earth's surface to the atmosphere and back to the surface again through evaporation, condensation, and precipitation

nitrogen fixation

process in which some types of bacteria in the soil change nitrogen gas into a form of nitrogen that plants can use

nitrogen cycle

model describing how nitrogen moves from the atmosphere to the soil, to living organisms, and then back to the atmosphere

carbon cycle

model describing how carbon molecules move between the living and nonliving world.


process in which producers make energy-rich nutrient molecules from chemicals

food web

model that shows the complex feeding relationships among organisms in a community

energy pyramid

model that shows the amount of energy available at each feeding level in an ecosystem

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

Voice Recording