| A | B |
|---|
| Abiotic | nonliving, physical features of the environment, including air, water, sunlight, soil, temperature, and climate |
| Atmosphere | air surrounding Earth, is made up of gases, including 78% nitrogen, 21% oxygen, and 0.;03% carbon dioxide |
| Biotic | features of an environment that alive or once were alive |
| Carbon cycle | model describing how carbon molecules move between the living and nonliving world |
| Chemosynthesis | process in which producers make energy-rich nutrient molecules from chemicals |
| Climate | average weather conditions of an area over time, including wind, temperature, and rainfall or other types of precipitation such as snow or sleet |
| Condensation | process that takes place when a gas changes to a liquid |
| Energy pyramid | model that shows the amount of energy available at each feeding level in an ecosystem |
| Evaporation | process that takes place when a liquid changes to a gas |
| Food web | model that shows the complex feeding relationships among organisms in a community |
| Nitrogen cycle | process in which some types of bacteria in the soil change nitrogen gas into a form of nitrogen that plants can use |
| Soil | 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 |
| 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 |
