CROSSWORD PUZZLE
Across
- 3. windpipe
- 8. air sacs
- 9. allows carbon dioxide to enter plant tissue
- 10. traps dirt in when inhaling
- 11. muscle used for breathing
- 12. voice box
Down
- 1. powerhouse of the cell
- 2. part of the throat behind the mouth and nasal cavity, and above the esophagus
- 4. structure in plants that allow gas exchange
- 5. prevents food from entering the airway
- 6. central organs of the respiratory system
- 7. system in charge of respiration