Environmental Science

5. - The process by which new species arise from existing species.
6. - The layer of gases surrounding the Earth.
7. - A group of organisms that can reproduce and have fertile offspring.
9. - The rigid outer layer of the Earth, consisting of the crust and upper mantle.
11. - The global sum of all ecosystems; the zone of life on Earth.
12. - The natural environment in which a species lives.
13. - The end of an organism or group of organisms; no longer in existence.

1. - All the water on Earth, including oceans, rivers, lakes, and glaciers.
2. - The variety of life in a particular habitat or ecosystem.
3. - A status for species that are likely to become endangered in the near future.
4. - A biological community interacting with its physical environment.
8. - A group of individuals of the same species living in a specific area.
10. - A status for a species that is at risk of extinction.