Across
- 1. break down dead bodies and waste materials
- 4. all the living organisms in an area and their environment are called
- 8. change ammonia into nitrates
- 10. in every living organism returns carbon dioxide to the air
- 11. can be used to identify unknown organism
- 12. take carbon dioxide from the air during photosynthesis
- 13. the position at which an organism feeds in a food chain
Down
- 2. sometimes two different species live closely with one another
- 3. helps to make proteins
- 4. passes from one organism to another in the form of food
- 5. all invertebrate animals with jointed legs
- 6. can not use nitrogen gas because it is too unreactive
- 7. a place where an organism lives
- 9. what are living organisms made out of