Across
- 3. survival of the fittest
- 4. study of body structure
- 7. earth is mostly comprised of _________
- 9. the name of Earth's ancient supercontinent
- 11. alternative energy that uses falling water
- 14. solar energy is __________
- 15. a resource that is not easily replaced
- 16. phenomenon responsible for shifting tectonic plates
- 18. earth's
- 19. a later of crust folds under another
Down
- 1. energy produced by the heat within the Earth
- 2. selective breeding for desired traits
- 5. a change in the genetic sequence
- 6. earth's crust is destroyed at the __________ boundaries
- 8. fracking poses a threat to which natural resource
- 10. small sequences in DNA
- 12. new crust is formed at _________ boundaries
- 13. humans have 23 pairs of __________
- 17. resistance to flow
- 20. came up with the theory of natural selection