| Term | Definition |
| Homeothermic | Maintain temperature from within [warm-blooded] |
| Species | Capable of reproducing |
| Primary Succession | Succession that occurs in an environment in which no trace of previous community was present |
| Secondary Succession | Succession that occurs after an existing community was disturbed |
| Osmoregulation | The homeostasis of a bodies water content |
| Temperate Grasslands | Hot extreme weather with many trees |
| Carrying Capacity | The ability of an ecosystem to maintain its organisms |
| Ammonia | A type of waste that fish give off |
| Taiga | Pine Trees; Pretty Cold |
| Arctic Tundra | Surrounds the ice and snow around the arctic region |
| Denitrifying Bacteria | They convert nitrites and nitrates into free nitrogen |
| Symbiosis | Specialized living relationships |
| Niche | A role of a species within a community |
| Mutualism | Both organisms benefit |
| Scavengers | Animals that feed on dead and decaying animals |
| Carnivore | A meat eater |
| Intraspecific competition | Competition between the same species |
| Ectothermic | Organisms that regulate their temperature by outside temperature |
| Photic Zone | The layer in a body of water that light reaches |
| Nitrates | Nitrogen usable by plants |
| Pioneer Community | The first species to inhabit an area |
| Nitrites | Nitrogen usable by animals |
| Commensalism | One organism benefits and the other is not affected |
| Population | Organisms of the same species that inhabit the same habitat |
| Herbivore | Plant eater |
| Parasitism | One organism is benefitted and the other is harmed |
| Competition | When two organisms occupy the same niche in the community |
| Desert | Hot during day/Cold during night |
| Consumers | All of the heterotrophs in the community |
| Predation | The act of hunting animals |
| Rainforest | Evenly moist and warm, lots of rain |
| Savannah | Dry and wet seasons |
| Interspecific Competition | Competition between different species |
| Nitrogen Fixing Bacteria | Converts atmospheric nitrogen to ammonia |
| Climax Community | The stable community that evolves and is at an equilibrium with the environment |
| Biomass | The weight of all the living things in an environment |
| Thermoregulation | The ability of an organism to maintain its temperature |
| Rhizobium | Converts nitrogen to nitrates |
| Biome | A region with certain characteristics |
| Temperate Forest | Seasons; no extreme weather |
| Biotic | All the living factors in an environment that affect organisms |
| Community | Various populations of different species from any given area |
| Free Nitrogen | Nitrogen in the atmosphere |
| Ecosystem | Biotic and abiotic factors living in an area |