Across
- 6. Reef A diverse underwater ecosystem built from coral
- 7. A community of living organisms interacting with their environment
- 11. Eruption The release of magma and gases from a volcano
- 13. Borealis The natural light display seen in polar regions
- 14. A geological formation that erupts with lava
- 15. A large sea wave caused by underwater earthquakes
- 16. The process by which soil and rock are worn away
- 18. A small celestial body that enters Earth's atmosphere
- 19. A gas essential for respiration in most living organisms
- 20. The force that attracts objects towards the Earth
Down
- 1. The process by which plants make their own food
- 2. The transfer of pollen from male to female parts of flowers
- 3. A cold, treeless biome found in polar regions
- 4. A state of inactivity during cold months
- 5. The largest body of water on Earth
- 8. System The collection of planets and other celestial bodies orbiting the Sun
- 9. The preserved remains of ancient organisms
- 10. Extinct reptiles that lived millions of years ago
- 12. The pigment in plants that makes them green
- 17. Insects that play a crucial role in pollination