| Term | Definition |
| Predator | A consumer that hunts other consumers. |
| Prey | A consumer that is hunted by other consumers. |
| Top of the Food Chain | A consumer that is not eaten by other consumers. |
| Arrows in a Food Chain | This means "gives energy to", "passes energy on to" |
| Consumer | A living organism that cannot make its own food, it must eat to stay alive. |
| Producer | An organism that produces or makes its own food, usually green plants. |
| Omnivore | A consumer that eats both plants and animals to get energy. |
| Carnivore | A consumer that only eats other consumers to get energy, meat eater. |
| Scavenger | A consumer that eats the leftovers from another consumer's kill. |
| First Order Consumer (Primary Consumer) | The first consumer shown in a food chain, It will be a type of herbivore. |
| Second Order Consumer ( Secondary Consumer) | The second consumer link in a food chain, it gets energy by eating another consumer. |
| Decomposer | A type of consumer that breaks down dead matter and returns nutrients to the soil. |
| Herbivore | A consumer that only gets energy form eating producers, a plant eater. |
| Competition | When two organisms live in the same area and need the same things. |
| Food Web | This shows the flow of energy in an ecosystem along many different pathways. |
| Food Chain | This shows the energy flow from one organism to another along one path. |
| Sun | Main source of energy for almost all ecosystems, producers use the energy to make their food. |
| Photosynthesis | The process of green plants using the sun's energy to make food. |
| Symbiosis | A relationship between two different species, it will benefit one or both organisms. |
| Parasitism | A win-lose relationship. One organism benefits by getting a home or food while the other organism is harmed. |
| Mutualism | A win-win relationship. Both organisms benefit from the reationship. |
| Commensalism | A win-no effect relationship. One organism benefits while the other organism is not effected. |
| Energy Pyramid | A graphic organizer that shows the amount of energy that is passed on in an ecosystem. |
| Parasite | An organism that lives off of another organism causing harm to it.(The winner in the relationship) |
| Host | The organism that provides a home or food for the parasite.(The loser in the relationship) |