Across
- 3. a gas that humans breath out
- 5. adding something
- 6. works with muscular system
- 7. smallest living thing
- 9. an organism that eats a producer
- 11. works with skeletal system
- 12. a living thing in an ecosystem
- 14. subtracting something
- 15. heart, lungs, trachea,
Down
- 1. an organism that eats and breaks down dead organisms
- 2. an organism that makes its own food
- 4. removes waste from body
- 8. a bunch of cells working together
- 10. any living thing
- 13. something humans breath in