Across
- 3. Composition of most endoskeletons
- 4. Protects your lungs and heart
- 7. Group of organs that play a major function
- 8. Tissues that can only contract or relax
- 10. The interaction of the skeleton and muscles
Down
- 1. Invertebrates do not have this
- 2. Muscles have to work this way
- 5. External covering in arthropods
- 6. Connects bones together
- 9. Basic unit of structure and function in the body