| Term | Definition |
| Theory | Explains something in the natural world using tested hypotheses, scientific facts, and logical inferences. |
| Law | Describes how the natural world behaves in specific circumstances. |
| Hypothesis | A testable statement about the natural world |
| Fact | observations that have been repeatedly confirmed |
| Evidence | Physical basis of facts |
| Inference | Logical assumptions based on evidence, but not directly observed. |
| Control | Keeping other factors constant, so that they don't influence the outcome of an experiment |
| Variable | A factor that can influence the outcome of an experiment |
| Carbohydrate | Complex sugars |
| Electrolyte | Salts in the form of ions. |
| Homeostasis | Balance |
| Diuretic | stops the absorption of water by the body |