science

2. a treeless plain found in the artic
6. an area of land that is periodically underwater
7. the mass of mostly microscopic organisms that float or drift Freely in fresh and marine enviorments
9. zone the zone of a lake or pond below the open-water
10. a large region characterized by a specific type of climate and certain type of plat
11. a treeless wetland ecosystem where plants such as grasses grow

1. a grass land that often has scattered trees and that is found in tropical and subtropical areas
3. a wetland ecosystem in which shrubs and trees grow
4. zone the zone of a pond or lake that extends from the littoral zone and that is as deep as light can reach
5. an area where freshwater from rivers mixes with saltwater from the ocean
8. zone the shallow zone of a lake or pond where light reaches the bottom and nurtures plants
9. a region that has little or no plant life, long periods without rain and extreme tempatures