Across
- 3. moisten the inhaled air, traps bacteria and dust
- 4. used to test for the presence of starch
- 11. one-cell thick
- 13. strengthen by C-shaped cartilage
- 14. combines and transport oxygen
- 15. sites for photosynthesis
- 16. a component of cigarette that is addictive
Down
- 1. our main respiratory organ
- 2. needed by plants during photosynthesis
- 5. movement of gaseous molecule from a region of high concentration to a region of lower concentration
- 6. a gas used during respiration
- 7. process of breathing out
- 8. food and air pass through here
- 9. vibrate and produce sound
- 10. opening on leaves that allow gaseous exchange
- 12. process of breathing in