Across
- 4. Air is made up of a __________ of gases.
- 6. Needed for respiration.
- 7. Mosquito larvae use breathing _____ to breathe.
- 9. Taken in by plants for photosynthesis.
- 10. Process of taking air into body and giving it out.
- 11. Most abundant gas in air.
Down
- 1. The tube that leads to the lungs from the nose.
- 2. Openings on leaves that allow gases to pass through.
- 3. The muscle that changes the size of the chest cavity.
- 5. The _____ system helps living things to breathe.
- 8. Gas _____ happens in the lungs for humans.