Across
- 2. The respiratory system of insects.
- 5. This happens to the intercostal muscles during inhalation.
- 6. Cancer causing chemical substances.
- 8. A condition of damaged alveoli.
- 11. MONOXIDE A colourless and odourless gas.
- 13. Place where the exchange of gaseous occurs.
- 14. Pathway of air into the nasal cavity.
- 16. At night or on a hot day, the guard cells become _______ and straight.
Down
- 1. A part of respiratory tract.
- 3. A dark red-coloured compound.
- 4. A substance in cigarette smoke that can cause addiction.
- 7. The skin of frogs is thin and very ______ to gas.
- 9. The concentration of oxygen in the air is lower at a _____ altitude.
- 10. In the breathing mechanism model, the rubber sheet represents the _________.
- 12. Process of water molecules diffuse from the low concentration region to high concentration region through semi-permeable membrane
- 15. One of the harmful substances in the air.