| A | B |
| producer | organism that makes its own food (autotroph) and produces organic molecules that serve as food for other organisms in its ecosystem |
| consumer | organism that obtains fod by eating producers (autotrophs) or other consumers |
| decomposer | organism that breaks down wastes and dead organisms |
| trophic level | feeding level in an ecosystem |
| food chain | pathway of food transfer from one trophic level to another |
| herbivore | consumer that eats only producers |
| carnivore | consumer that eats only other consumers |
| omnivore | consumer that eats both producers and consumers |
| primary consumer | consumer that feeds directly on producers |
| secondary consumer | consumer that eats primary consumers |
| tertiary consumer | consumer that eats secondary consumers |
| detritus | wastes and remains of dead organisms |
| food web | pattern of feeding in an ecosystem consisting of interconnected and branching food chains |
| biomass | organic material manufactured by producers |
| primary productivity | rate at which producers in an ecosystem build biomass |
| energy pyramid | diagram representing energy loss from one trophic level to the next |
| biomass pyramid | diagram representing the biomass in each trophic level of an ecosystem |
| pyramid of numbers | representation of the number of individual organisms in each trophic level of an ecosystem |
| nitrogen fixation | process by which certain bacteria convert nitrogen gas to ammonia |
| nitrification | process by which certain bacteria convert ammonium to nitrates |
| transpiration | evaporation of water from a plant's leaves |
| deforestation | clearing of forests for agriculture, lumber or other uses |
| greenhouse effect | process by which atmospheric gases trap heat close to Earth's surface and prevent it from escaping into space |
| global warming | rise in Earth's average temperature |
| eutrophication | rapid growth of algae in bodies of water, due to high levels of nitrogen and often phosphate |
| acid rain | precipitation that contains nitric and/or sulfuric acids |
| pollution | addition of substances to the environment that result in a negative effect |
| biological magnification | process by which pollutants become more concentrated in successive trophic levels of a food web |
| ozone | atmospheric gas that absorbs ultraviolet radiation, shielding organisms from its damaging effects |
| biodiversity | variety of life on Earth |
| overexploitation | practice of harvesting or hunting to such a degree that remaining individuals may not be able to replenish the population |
| conservation biology | application of biology to counter the loss of biodiversity |
| zoned reserve | area of land that is relatively undisturbed by humans and is surrounded by buffere zones that are minimally impacted by humans |
| buffer zone | are of a reserve that is minimally impacted by humans |
| sustainable development | use of natural resources in a way that allows them to renew themselves and be available for the future |