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38 Cards in this Set

  • Front
  • Back
population density
# of individuals per unit area
movement of individuals into an area occupied by an existing population
movement of individuals out of an area
exponential growth
growth pattern in which the individuals in a population reproduce at a constant rate
logistic growth
growth pattern in which a population's growth rate slows or stops following a period of exponential growth
carrying capacity
largest number of individuals of a population that a given environment can support
limiting factor
factor that causes the growth of a population to decrease
density-dependent limiting factor
limiting factor that depends on population size
predator-prey relationship
mechanism of population control in which a population is regulated by predation
density-independent limiting factor
limiting factor that affects all populations in similar ways, regardless of population size
scientific study of human populations
demographic transition
change in a population from high birth and death rates to low birth and death rates
age-structure diagram
graph of the numbers of males and females within different age groups of a population
the practice of farming
farming strategy in which large fields are planted with a single crop, year after year
green revolution
the development of highly effective crop strains and the use of modern agricultural techniques to increase yields of food crops
renewable resource
resource that can regenerate quickly and that is replaceable
nonrenewable resource
resource that cannot be replenished by natural processes
sustainable development
using natural resources at a rate that does not deplete them
soil erosion
wearing away of surface soil by water and wind
in areas with dry climates, a process caused by a combination of poor farming practices, overgrazing, and drought that turns productive land into desert
destruction of forrests
the raising of aquatic organisms for human consumption
mixture of chemicals that occurs as a gray-brown haze in the atmosphere
harmful material that can enter the biosphere through the land, air, or water
acid rain
rain containing nitric and sulfuric acids
biological diversity; the sum total of the variety of organisms in the biosphere
ecosystem diversity
variety of habitats, living communities, and ecological processes in the living world
species diversity
number of different species in the biosphere
genetic diversity
sumtotal of all the different forms of genetic information carried by all organisms living on Earth today
disappearance of a species from all parts of its geographical range
endangered species
species whose population size is rapidly declining & will become extinct if the trend conditions
habitat fragmentation
splitting of ecosystems into small fragments
biological maginification
increasing concentration of a harmful substance in organisms at higher trophic levels in a food chain or food web
invasive species
plants & animals that have migrated to places where they are not native
wise management of natural resources, including the preservation of habitats and wildlife
ozone layer
atmospheric layer in which ozone gas is realtively concentrated
global warming
increase in the average temperatures on Earth