Across
- 2. layers of gases held up by gravity
- 6. when organisms rely on each other
- 7. water found on earth surface
- 10. living organisms
- 12. variety of organisms in an ecosystem
- 13. doesn't produce their own food
- 15. the removal of forests
- 17. building block for part of the cell
- 18. outer shell of the earth
Down
- 1. nutrient needed for the survival of organism
- 3. mixture of sand, silt, clay, and hummus
- 4. when one organism consumes another
- 5. uses energy from the sun
- 8. all areas where life is found
- 9. a community of interacting organisms
- 11. non-living things
- 12. layer under all the soil made up of rocks
- 14. one of the most common elements on earth
- 16. layer of soil made up of decomposed plants