| A | B |
| Environment | consists of all the living and nonliving things with which an organism may interact |
| Ecology | Study of the relationships and interactions of living things with one another and their environment |
| Ecosystems | Consists of all the living and nonliving things in a given area that interact with one another |
| Communities | The livivg part of any ecosystem all the different organisms that live together in that area |
| Populations | Group of organisms of the same type,or species, living together in the same area |
| Habitats | Place in which an organism lives |
| Producers | Source of all the food in an ecosystem |
| Consumers | Organisms that feed directly or indirectly on producers |
| Decomposers | Break down dead organisms into simpler substances |
| Food Chain | Represents a series of events in which food and evergy are transferred from one organism in an ecosystem to another. |
| Food Web | All the food chains in an ecosystem that are connected |
| Competition | Struggle among living things to get the proper amount of food,water and energy |
| Predator | Animal that kills and eats other animals |
| Prey | Organism that is killed and eaten by a predator |
| Symbiosis | Close relationship between two organisms in which one organism lives near,on,or even inside another organnnnism and in which at least one benefits |
| Commensalism | One organism benefits,and one not harmed or benefits |
| Mutualism | Both organisms benefit |
| Parasitism | One benefits,one harmed |
| Parasite | Organism that feeds on other living organisms |
| Host | Organism in which another organism lives |