Across
- 4. Trees that lose their leaves in fall.
- 5. Event when multiple meteors are observed.
- 6. Measure of heat.
- 9. Seasonal movement of animals.
- 11. Process by which plants make food using sunlight.
- 14. Changes in weather and daylight.
- 16. Our planetary system.
- 18. Period of dormancy in animals.
- 19. Climate conditions at a particular time and place.
Down
- 1. Breakdown of organic matter.
- 2. Study of weather and climate.
- 3. Layer of gases surrounding Earth.
- 7. Regions of Earth where life exists.
- 8. Community of living organisms.
- 10. Material that retains heat.
- 12. Force that attracts objects toward one another.
- 13. Leaves of trees and plants.
- 15. Large system of stars.
- 17. Green pigment in plants.
- 20. Time when day and night are of equal length.