| A | B |
|---|
| ecology | study of the interactions among living things and their surroundings |
| community | collection of all of the different populations that live in one area |
| ecosystem | collection of organisms and nonliving things, such as climate, soil, water, and rocks, in the area |
| biome | regional or global community of organisms characterized by the climate conditions and plant communities that thrive there |
| biotic | living things, such as plants, animals, fungi, and bacteria |
| abiotic | nonliving factor in an ecosystem, such as moisture, temperature, wind, sunlight, soil, and minerals |
| biodiversity | variety of life within an area |
| keystone species | organism that has an unusually large effect on its ecosystem |
| producer | organism that obtains its energy from abiotic sources, such as sunlight or inorganic chemicals |
| autotroph | organism that obtains its energy from abiotic sources |
| consumer | organism that obtains its energy and nutrients by eating other organisms |
| hetertroph | organism that obtains its energy and nutreints by consuming other organisms |
| chemosynthesis | a process by which ATP is synthesized by using chemicals as an energy source instead of light |
| food chain | model that links organisms by their feeding relationships |
| herbivore | organism that eats only plants |
| carnivore | organism that obtains energy by eating only animals |
| omnivore | organism that eats both plants and animals |
| detritivore | organism that eats dead organic matter |
| decomposer | detritivore that breaks down organic matter into simpler compounds, returning nutrients back into an ecosystem |
| specialist | consumer that eats only one type of organism |
| generalist | species that does not rely on a single source of prey |
| trophic level | level of nourishment in a food chain |
| food web | model that shows the complex network of feeding relationships within an ecosystem |
| hydrologic cycle | pathway of water from the atmosphere to Earth's surface, below ground, and back |
| biogeochemical cycle | movement of a chemical through the biological and ecological, or living and nonliving, parts of an ecosystem |
| nitrogen fixation | process by which certain types of bacteria convert gaseous nitrogen into nitrogen compounds |
| biomass | total dry mass of all organisms in a given area |
| energy pyramid | diagram that compares energy used by producers, primary consumers, and other trophic levels |
