| A | B |
|---|
| Cell | The basic unit of structure and function of all living things. |
| Tissue | A group of similar cells doing the same job. |
| Organ | A group of similar tissues performing a job. |
| Organ System | Organs working together to perform a set of related tasks. |
| Organism | An entire living thing that carries out all the basic life functions. |
| Skeletal System | The system that protects and supports the body. |
| Muscular System | The system that supports the body and enables it to move. |
| Digestive System | The system that receives, breaks down, transports and absorbs food throughout the body. |
| Circulatory System | The system that carries needed substances to the cells of the body while carrying waste products away from the cells. "The River of Life" |
| Respiratory System | The system that brings oxygen into and removes carbon dioxide from the body. |
| Excretory System | The system that collects and removes waste products from the body. |
| Nervous System | The system that communicates information throughout the body and controls the body's response to stimuli. |
| Endocrine System | The system that produces chemical messengers, hormones, that help to regulate and control many of the body's internal functions. |
| Immune System | The system that acts as the body's defense system against disease causing organisms. |
| Reproductive System | The system that allows living things to produce new individuals of the same type. |
