Across
- 2. Number of offspring needed to keep population steady; 2.1 for humans
- 4. All the organisms of one species in an area
- 5. Organism that must eat other organisms for energy
- 7. Succession that begins with bare rock and is slower
- 8. Relationship where one species benefits, the other is unaffected
- 11. Succession that begins with soil and is faster
- 12. Organism that can make its own food
- 13. Process where organisms use light to make food
- 14. Study of human populations
- 17. Type of gas that traps heat in the atmosphere
- 18. All the organisms of all species in an area
- 19. Stretching of waves by objects moving away
- 20. Energy type that can be easily replaced; wind, solar, hydro
Down
- 1. Rocks made from other rocks under heat and pressure
- 3. Rocks made from pieces of other rocks or organisms
- 6. Relationship where one species benefits, the other is harmed
- 9. Energy type that cannot be easily replaced; coal, oil, nuclear
- 10. Squeezing of waves by objects getting closer
- 11. All continents joined in one landmass; Pangaea
- 15. Rocks made from molten rock; magma or lava
- 16. Relationship where both species benefit