Across
- 5. Anything that has mass and takes up space
- 8. To shed an old outer covering so that it can be replaced with a new one
- 11. The period of time during which an embryo develops before being born
- 12. Organisms that depend on other organisms for good
- 15. A fine dust that contains the sperm of seed-producing plants
- 16. Number The number of protons in an atom - unique to each type of atom
- 18. Requiring Oxygen
- 20. The study of cells
Down
- 1. The study of life processes in an organism
- 2. The science that studies how characteristics are passed from parent to offspring
- 3. An organism that causes disease
- 4. Blood vessels that carry blood away from the heart
- 6. The maintenace of stable internal conditions
- 7. Proteins in your immune system used to attack specific antigens
- 9. A group of ecosystems classified by climate and plant life
- 10. Chemicals that result when tow or more atoms join together chemically
- 13. A special structure used by an organism to anchor itself
- 14. Animals that possess a backbone
- 17. Preserved remains of once living organisms
- 19. The study of the interactions between living and nonliving things