Across
- 3. Opening for gas exchange in plants
- 4. A part of science that studies matter and reactions
- 8. The amount of matter in an object
- 9. Substances that are produced in a chemical reaction
- 13. Pulmonary respiratory organs
- 15. A process by which green plants produce food
- 17. A gas that turns lime water turbid
- 18. The amount of space an object occupies
- 19. Opening to release carbon dioxide in fish
Down
- 1. An opening for tracheal respiration
- 2. A part of science that studies living things
- 5. Inhalation and exhalation
- 6. Non-chloropyllic organisms necessary for fermentation
- 7. Substances that combine together in a chemical reaction
- 10. Anything that has mass and occupies space
- 11. A part of science that studies forces, speed and movement
- 12. Reaction that releases heat
- 14. Reaction that absorbs heat
- 16. Covers the body and can be used for respiration in some animals
- 19. A gas inhaled by living things