| A | B |
|---|
| ecosystem | all the living and nonliving things that interact in a particular area. |
| habitat | the place where an organism lives and that provides the things the organism needs. |
| biotic factors | the living parts of an ecosystem (plants, animals, bacteria, fungi, worms). |
| abiotic factors | the nonliving parts of an ecosystem (water, soild, sunlight, oxygen, temperature). |
| population | all the members of one species in a particular area. |
| society | a closely related population of animals that work together for the benefit of the whole group. |
| community | all the different populations that live together in an area |
| ecology | the study of how all the living organisms interact with each other and their environment. |
| levels of organization | organism-population-community-ecosystem |
| biomass | the total amount of living matter and the remains of dead organisms in an area. |
| decay | the brak down of material in biomass by bacteria and other decomposers (heat is released) |
| nitrogen fixation | decomposers make nitrogen so that other organisms can use it. Organisms cannot use free nitrogen from the air. |
