| A | B |
|---|
| Biomes | Very large ecosystems that contain a number of smaller but related ecosystems within them. |
| Tundra | A cold largeley treeless biome. |
| Permafrost | a permanently frozen layer of soil under the surface. |
| Tropical Rainforest | Occur near the equator and are known as the tropics with stable temperatures and an abundance of rainfall. |
| Canopy | The treetops in the tropical rainforest. |
| Epiphyte | When a small plant lives on the branches of a larger plant to obtain sunlight. |
| Coniferous Tree | Trees that bear seeds on cones and tend to be evergreen. |
| Deciduous Tree | Trees that shed their leaves every year. |
| Temperate Deciduous Forest | A biome with pronounced seasons and precipitation unevenly distributed throughout the year. |
| Taiga | The biome located south of the tundra and north of the temperate deciduous forest dominated by coniferous trees. |
| Temperate Grassland | A biome that usually forms on the interior of a continent with less rainfall than the temperate deciduous forest. |
| Savanna | Tropical or temperate grasslands that have scattered deciduous trees and shrubs. |
| Chaparral | a biome dominated by dense, spiny shrubs and has scattered clumps of coniferous trees. |
| Desert | biomes that receive less than 25 cm of rainfall per year. |
| aphotic zone | The area of the ocean that is cold and dark where light cannot penetrate and photosynthesis cannot occur. |
| photic zone | The part of the ocean that receives sunlight. |
| intertidal zone | The area of shoreline that is twice daily covered by water during high tide and exposed to air during low tide. |
| neritic zone | Extends from the intertidal zone over the continental shelf and to relatively shallow water depths of about 180 m. |
| oceanic zone | The deepest part of the ocean and contains fewer species than the netritic zone. |
| pelagic zone | The open ocean. |
| benthic zone | The ocean bottom. |
| plankton | Communities of small organisms that drift with the ocean currents. |
| estuary | Where freshwater rivers and streams flow into the sea. |
| eutrophic lake | Lakes that are rich in organic matter and vegetation. |
| oligotrophic lake | Lakes that contain little organic matter. |
| freshwater wetland | Areas of land that are covered with fresh water for at least part of each year. |
