Across
- 3. White blood cells help fight this.
- 5. This gas is transported by red blood cells to the body cells.
- 7. This is a protein that helps red blood cells carry oxygen.
- 8. Plant cells have this around their cells to help them stand up.
- 9. The largest artery in the human body.
- 10. The main organ of the respiratory system.
Down
- 1. You breathe this gas out.
- 2. The powerhouse of the cell.
- 4. Makes energy from sunlight in plant cells.
- 6. The main organ of the circulatory system.