| A | B |
|---|
| tropics | the region that receives the most solar radiation; extends between latitudes 23.5 degrees north and 23.5 degrees south of the equator |
| polar zone | the zones that receive solar radiation at an angle and are the coldest areas on Earth; extend from the poles to 66.5 degrees north and south latitudes |
| temperate zone | the two zones of moderate, seasonal weather that exist between the tropics and the polar regions |
| adaptation | any structural or behavioral characteristic organisms have developed over time that helps them survive in a particular environment |
| hibernation | a period of inactivity during which an animal's body temperature drops and its body processes slow down |
| season | a regular, short-term period of change in the climate of an area due to changes in the amount of solar radiation the area receives |
| El Nino | a climatic event that occurs when trade winds weaken west of Peru and whose effect can be felt worldwide |
| greenhouse effect | natural heating caused by the atmospheric gases trapping heat at Earth's surface |
| global warming | the rise in global temperatures due to an increased greenhouse effect |
| deforestation | the removal of forests, mostly to clear land for farming, construction, mining, and drilling for oil |
| reforestation | the planting of a large number of trees |
