Chapter 7: Oxygen Cycle and Carbon Dioxide Cycle

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