Across
- 7. plants release water vapor into the air
- 10. plants and animals that originally live in an ecosystem
- 11. a regular pattern of change
- 13. gradual changes in the populations of organisms in an ecosystem
- 14. when water changes from a liquid to water vapor
- 15. any physical hazard to life caused by having too much or too little of things needed for life
Down
- 1. when water falls to earth either as a liquid or a solid
- 2. when water changes from water vapor to a liquid
- 3. organisms use sugar molecules and oxygen to produce energy
- 4. plants and animals that are not native to an area and can cause harm
- 5. plants use water, carbon dioxide, and sunlight to create sugar and oxygen
- 6. a population so small that it is in danger of becoming extinct
- 8. a species whose last known member has died
- 9. regular divisions of the year
- 12. precipitation that soaks into the ground and is stored