| A | B |
|---|
| Lithosphere | Crust and uppermost mantle; divided into tectonic plates |
| Asthenosphere | Soft middle mantle; heated by outer core |
| Lower mantle | Solid rock |
| Divergent boundaries | Rising magma pushes plates apart. |
| Transform boundaries | Plates slip and grind alongside one another. |
| Subduction | One plate slides beneath another. |
| Mountain-building | Both plates are uplifted. |
| Biosphere | The part of Earth in which living and nonliving things interact |
| Atmosphere | Contains the gases that organisms need, such as oxygen; keeps Earth warm enough to support life |
| Earth’s water | (97.5%) is salt water. |
| .5% of Earth’s water | is unfrozen fresh water usable for drinking or irrigation. |
| Earth’s available fresh water | includes surface water and ground water |
| groundwater | can take hundreds or even thousands of years to recharge completely. |
| Organisms | require several dozen nutrients, such as nitrogen, phosphorus, and carbon, to survive. |
| Nutrients | matter that organisms require for their life processes |
| Nutrients that cycle through all of Earth's spheres and organisms | carbon, oxygen, phosphorus, and nitrogen |
| consumers | are organisms, mainly animals, that must eat other oganisms to obtain nutrients. |
| decomposers | are organisms such as bacteria and fungi that break down wastes and dead organisms. |
| cellular respiration | is the process by which organisms use oxygen to release the chemical energy of sugars and release CO2 and water |
| Sink | is a reservoir of a substance that accepts more of that substance than it releases. |
| Sediments | remains settle in here when organisms die |
| Limestone | and other sedimentary rock make up the largest reservoir of carbon |
| worlds oceans | second largest carbon reservoir |
| hypoxia | extremely low levels of oxygen in a body of water |
