| A | B |
|---|
| population | a group of organisms of the same species and a certain area and time |
| population density | how crowded a popuation is |
| predator-prey relationship | where population is regulated by predation. |
| birth rate | the number of births per period of time |
| death rate | the number of deaths per period of time |
| life expectancy | how long on average an individual is expected to live |
| age structure diagram | the distrubution of ages in a population |
| demography | the study of human population. |
| population growth rate | the amount a population changes in size in a given time |
| immigration | movement of individuals into a population |
| emmigration | movement of individuals out of a population |
| exponential growth | a pattern of population growth that follows a J curve: growing indefinitely |
| limiting factor | any factor that restrains growth of a population (space) |
| logistic growth | build on exponential model, but accounts for limiting factors |
| carrying capacity | the number of individuals the environment can support over long periods of time |
| density-dependent factor | population matters, because these are factors that decrease like resources or nest sites |
| density-independent factor | population size doesn't matter, equal amounts will be reduced (weather) |
| demographic transition | a dramatic change in birth and death rates. |
| demographic transition | a model that shows how some populations are growing and some are shrinking |
