Across
- 2. the atmosphere has always had the same composition (t/f)
- 3. if one organism has a better chance of surviving than another, it is more ____
- 5. A staph infection that is resistant to most antibiotics
- 6. individuals can evolve (t/f)
- 8. change over time
- 9. the preserved remains of a once-living organism
- 10. all organisms share a common
- 14. chemicals that kill pests
- 15. when organisms are separated geographically, the _______ _______ is cut off
- 17. have no membrane-bound organelles
- 18. Y-shaped molecules that mark or kill pathogens
- 19. all living organisms cells have ribosomes (t/f)
Down
- 1. _______ structures are left over from ancestors
- 4. when 2 or more organisms are struggling for the same resource
- 7. when all organisms in a species die
- 11. all organisms have a common ancestor
- 12. is evolution slow or fast?
- 13. the variety of living things on earth
- 16. the man who discovered natural selection
- 18. a trait that helps an organism survive