Across
- 2. Gas needed for aerobic respiration
- 4. Smallest part of any living thing
- 7. Substance needed for a chemical reaction to happen
- 9. Device used in the lab to look at very small things
- 10. Type of unicellular organism that surrounds and digests its food
- 13. Sheet of muscle under the lungs that helps with breathing
- 15. Piece of glass used to display objects under the microscope
- 16. Tiny bag in the lung that increases the lung's surface area
- 18. One of the bones surrounding the thorax
- 19. Breathe in
- 21. Many similar cells joined together
- 22. Colour of blood cell that has no nucleus
Down
- 1. All cells have one of these surrounding the cytoplasm
- 3. Main organ in the circulatory system
- 5. Green part that helps a plant cell to make food
- 6. Hole filled with liquid, found in many cells
- 8. Surface area _______ volume = surface area to volume ratio
- 11. Main organ of the nervous system
- 12. Plant cells are surrounded by a cell ______
- 14. This part controls the cell
- 17. Living thing
- 20. Cells respire in order to release this