| A | B |
|---|
| Producer | organisms that can make their own food. Use the energy from the sun for photosynthesis. |
| Consumer | organism that cannot make its own food. |
| Herbivore | consumers that eat only plants |
| Carnivores | consumers that eat only animals |
| Omniovres | consumers that eat both plants and animals. |
| Scavanger | a carnivore that feeds on the bodies of dead organisms. |
| Decomposers | break down biotic wastes and dead organisms and return the raw materials to the ecosystem. |
| Sun | the main source of energy for all life on Earth. |
| Food chain | a series of events in which one organism eats another and obtains energy |
| Food web | a series of many overlapping food chains in an ecosystem |
| First level consumers | organisms that feed directly on producers |
| Second level consumers | eat the first level consumers |
| Third level consumers | eat the second level consumers |
| Energy pyramid | shows the amount of energy that moves from one level to another in a food web. |
| The amount of energy transferred from one energy level to the next | only 10%. |
| The amount of energy converted into heat at each energy level | about 90%. |
| water cycle | there processes of evaporation, condensation ad precipitation. |
| evaporation | the process by which liquid water absorbs enough energy to become a gas. |
| condensation | the process by which a gas changes back into a liquid |
| precipitation | when the liquid water becomes large enough and falls back to Earth |
| Carbon cycle | producers take in carbon dioxide to make glucose; consumers eat the producers and return the carbon in the glucose back into the environment as carbon dioxide. |
| Oxygen cycle | producers release oxygen into the environment during photosynthesis; consumers breathe in the oxygen and use it to break down food to make energy. |
| Nitrogen cycle | nitrogen is cycled from the air and the soil into living things and then back into the air and soil. |
| Nitrogen Fixation | the process of taking free nitrogen in the air and the soil and fixing it, or combining it, into other compounds that can be used by other living things. Bacteria usually do this. |
| Biodiversity | the number of different species that live in an area |
| extinction | the complete dying out of a species |
| habitat destruction | the loss of a natural habitat |
| Ponds and rivers | freshwater ecosystems |
| Intertidal zone | part of the marine ecosystem; covered by water during high tide; exposed to the air during low tide. |
| Biome | group of land ecosystems with similar climates |
| niche | the role of an organism in its environment |
