| A | B |
|---|
| Ponds, runoff, & streams | Surface water |
| ozone | This blocks ultraviolet radiation from reaching the Earth's surface |
| carbon dioxide | A gas that contributes most to the greenhouse effect |
| atmosphere | The layer of air that surrounds Earth |
| light | The most important requirement for all living things |
| Energy consumed by organisms | is stored in fat and sugar molecules |
| Producers | obtain energy directly from the sun |
| Killer whales | can be found at the top of an energy pyramid |
| Humans | are omnivores |
| latitude | The distance north or south of the equator, as measured in degrees |
| Grassland biomes | Susceptible to fires, low to moderate rainfall, few to no trees |
| Salt marsh | Ecosystem with the highest level of salinity |
| littoral zone | Has diverse and abundant aquatic life |
| benthic zone | Has cool and dark water |
| parasite | organism that feeds on the body fluids of another organism but does not kill it |
| Commensal relationship | When one organism benefits and the other is not harmed |
