Across
- 2. Layer protecting Earth from UV rays
- 4. Tiny finger-like projections in the small intestine
- 6. Green pigment in leaves
- 8. Organ that pumps blood
- 9. Main source of energy
- 10. Process by which green plants prepare food
- 14. Organism that feeds on dead matter
- 16. Water movement through plants
Down
- 1. Process of breathing
- 3. Harmful change in environment
- 5. Organ where digestion begins
- 7. Natural home of organisms
- 8. Plant-eating animals
- 9. Tiny pores on leaves
- 11. Gas required for respiration
- 12. Removal of wastes from body
- 13. Interaction of organisms with surroundings
- 15. Fluid connective tissue in humans