Across
- 2. Gas essential for respiration
- 7. Organ system responsible for transporting blood
- 9. Green pigment in plants that absorbs sunlight
- 10. Type of circuit where current has only one path
- 11. Natural satellite of Earth
Down
- 1. The nearest star to Earth
- 3. The pull of the Earth on objects
- 4. The planet known as the 'Red Planet'
- 5. Change of state from liquid to gas
- 6. Simplest form of matter, made up of protons, neutrons and electrons
- 7. Non-renewable fossil fuel formed from ancient plants
- 8. Smallest unit of life