| A | B |
|---|
| population density | # of individuals per unit area |
| immigration | movement into an area |
| emigration | movement out of an area |
| exponential growth | individuals reproduce at a constant rate producing a j-shaped curve |
| logistic growth | population's growth slows or stops producing an s-shaped curve |
| carrying capacity | largest # of individuals that an environment can support |
| limiting factor | causes population growth to decrease |
| density-dependent limiting factor | limiting only when the population density reaches a certain level |
| density-independent limiting factor | Affect all populations in similar ways, regardless of size |
| renewable resource | can regenerate quickly and is replaceable |
| nonrenewable resource | cannot be replenished through natural processes |
| soil erosion | wearing away by water and wind |
| desertification | land turned to desert |
| deforestation | loss of forests |
| smog | mixture of chemicals that occurs as a gray-brown haze in the atmosphere |
| acid rain | contains nitric and sulfuric compounds with water vapor in the air |
| biodiversity | sum total of the genetically based variety of organisms in a biosphere |
| biological magnification | concentrations of harmful substances increase in organisms at higher trophic levels in a food chain |
| invasive species | plants and animals that have migrated to place where they are not native |
| conservation | wise management of natural resources |
| carrying capacity | the maximum number of individuals of a species that an area can accomodate |
| demography | the scientific study of human populations |
| demographic transition | the dramatic change in human populations due to a change in birth or death rates |
| reproductive potential | the maximum number of offspring that an individual can produce |
| competition | two or more organisms trying to use the same limited resources |
| predation | one organism killing and feeding on another organism |
