Across
- 3. common or rare certain traits are among a group
- 4. key mechanism of evolution
- 9. cell that has a nucleus and membrane bound organelles
- 13. actions or habits that organisms perform to survive
- 14. living things change or adjust to the environment
- 15. tiny, single-celled organisms
- 18. a simple form of asexual reproduction
- 20. species becoming extinct
Down
- 1. non-living germ that invades living cell
- 2. single-celled organism that lacks a nucleus
- 5. the differences in physical or behavioral characteristics
- 6. differences in genes
- 7. adjustment within an organism's cells, enhancing survival
- 8. reproduction involving only one parent
- 10. bacteria evolve defenses to survive drugs designed to kill them
- 11. organisms best adapted to their environment are more likely to survive,
- 12. bodily characteristic that an organism has to help it survive
- 16. gene that determines a particular trait
- 17. two parents combine their genetic material
- 19. populations evolve to become distinct species