| A | B |
|---|
| abiotic | nonliving, physical features of the environment, including air, water, sunlight, soil, temperature, and climate |
| atmosphere | air surrounding Earth; made up of gasses: 78% nitrogen, 21% oxygen, 0.94% argon, and 0.03% CO2 |
| biotic | features of the environment that are alive or were once alive |
| carbon cycle | model describing how carbon molecules move between the living and nonliving world |
| chmosynthesis | 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/other precipitation |
| 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 | model describing how nitrogen moves from the atmosphere to the soil, to living organisms, and then back to the atmosphere |
| nitrogen fixation | process in which some types of bacteria can form the nitrogen compounds that plants need |
| 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 |
