| A | B |
|---|
| carbon cycle | Process by which carbon compounds are converted in the environment by converting carbon dioxide |
| water cycle | Process by which water circulates between the Earth’s oceans, atmosphere, and land involving precipitation, drainage in streams and rivers, and return to the atmosphere by evaporation and transpiration. |
| nitrogen cycle | Process by which nitrogen and its compounds are converted in the environment and in living organisms, including nitrogen fixation and decomposition. |
| photosynthesis | Process by which green plants use sunlight, carbon dioxide, and water to create oxygen and glucose. |
| organism | An individual animal, plant, or single-celled life form. |
| bacteria | Member of unicellular microorganisms that have cell walls but lack organelles and an organized nucleus. |
| fungi | Any group of unicellular or multicellular spore-producing organisms feeding on organic matter including molds, yeast, mushrooms, and toadstools. |
| third order (tertiary consumers) | A carnivore at the topmost level in a food chain that feeds on other carnivores; and animal that feeds only on secondary consumers. |
| food chain | A series of events in which one organism eats another. |
| food web | The pattern of overlapping food chains in an ecosystem. |
| terrestrial ecosystems | An ecosystem found only on landforms; tundra, coniferous forest, deciduous forest, tropical rainforest, grassland, and desert. |
| freshwater ecosystem | Include lakes, ponds, rivers, streams, springs, swamps, and wetlands; water has little salt content. |
| marine ecosystems | Salt marshes, intertidal zones, estuaries, lagoons, mangroves, coral reefs, deep sea, and sea floor; water has salt content. |
| energy pyramid | A diagram that shows the amount of energy that moves from one feeding level to another in a food web. |
| producer | An organism that can make its own food. |
| autotroph | An organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide. |
| consumer | An organism that obtains energy by feeding on other organisms. |
| heterotroph | A species that influences the survival of many other species in an ecosystem. |
| first order consumer | Animals that eat plants (producers), first step in the food chain, second-level of the energy pyramid. |
| second order consumer | Organism that eats or derives nutrients from the first order consumer. |
| herbivore | An animal that eats only plants. |
| carnivore | An animal that eats only other animals |
| omnivore | An animal that eats both plants and animals. |
| scavenger | A carnivore that feeds on the bodies of dead organisms. |
| decomposer | An organism that breaks down large chemicals from dead organisms into small chemicals and returns important materials to the soil and water. |
| evaporation | The process by which molecules of a liquid absorb energy and change to the gas state. |
| condensation | The process by which a gas changes to a liquid |
| precipitation | Rain, snow, sleet, or hail. |
| nitrogen fixation | The process of changing free nitrogen gas into a usable form. |
| nodules | Bumps on the roots of certain plants that house nitrogen-fixing bacteria. |
| biome | A group of ecosystems with similar climates and organisms. |
| canopy | A leafy roof formed by tall trees. |
| understory | A layer of shorter plants that grow in the shade of a forest canopy. |
| desert | An area in which the yearly amount of evaporation is greater than the amount of precipitation. |
| grassland | An area populated by grasses that gets 25 to 75 centimeters of rain each year. |
| savanna | A grassland close to the equator. |
| deciduous trees | Trees that shed their leaves and grow new ones each year. |
| coniferous trees | Trees that produce their seeds in cones and have needle-shaped leaves. |
| tundra | An extremely cold, dry biome. |
| permafrost | Soil that is frozen all year. |
| estuary | A habitat in which the fresh water of a river meets the salt water of the ocean. |
| rainforest | A dense forest rich in biodiversity, found typically in tropical areas with consistently heavy rainfall. |
| deciduous forest | Temperate deciduous forests are dominated by trees that lose their leaves each summer in areas with warm, moist summers and mild winters |
| coniferous forest | Temperate coniferous forests are found in temperate regions with warm summers, cool winters, and adequate rainfall characterized by con-bearing, needle leaved trees. |
