| A | B |
|---|
| autotrophs | use sun for energy |
| producer | can produce food |
| photosynthesis | use light energy to power chemical reaction |
| heterotruphs | obtains energy from the foods it consumes |
| consumer | relies on other organisms for its energy and food supply |
| herbivore | obtains energy by eating only plants |
| omnivore | obtains energy by eating both plants and animals |
| carnivore | organism that only eats meat |
| decomposer | breaks down and obtains energy from dead organic matter |
| food chain | models the flow of energy through organisms in a community |
| food web | network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem |
| trophic level | step in a food chain or food web |
| ecological pyramid | diagram that shows the relative amounts of energy |
| evaporation | process by which water changes from a liquid into an atmospheric gas |
| transpiration | water leaves plant |
| nutrient | chemical substance that an organism requires to live |
| nitrogent fixation | process of converting nitrogen has into ammonia |
| Growth Rate | total change in number of individuals over time |
| Population | Group of organisms of the same species that live in a particular area |
| Exponential Growth | occurs when the rate of population growth in each new generation is a multiple of previous generation |
| Emmigration | movement of organisms out of an area |
| Immigration | movement of organisms into an area |
| Limiting factors | any biotic or abiotic resourc in the environment that limits the size of a population |
| Carrying capacity | the number of individuals in a population that an environment can support over a relatively long period of time |
| Density-Dependent Limiting Factors | become limiting only when the population density reaches a certain level |
| Population Density | number of organisms per unit of space |
| Density-Independent Limiting Factors | affect all populations in the same way, regardless of their density |
| Scavenger | consumer that feeds on the tissues of dead animals |
| Decomposer | eats waste and dead organic matter from all tropic levels |
| Carbon Cycle | movement of carbon through the environment |
| Nitrogen Cycle | pathway of nitrogen through the environment |
| Denitrification | Process of returning nitrogen to the atmosphere |
| Water Cycle | Continual movement of water from the Earth's surface to the atmosphere and back to the surface again |
