Chapter 7 Vocab: Enviro

affluence

having a lot of money.

age distribution

the comparative percentages of different age groups within a population.

asexual reproduction

divide to form new individuals that are identical to the original parent figure.

biotic potential

the inherent productive capacity.

birthrate

the number of individuals born per thousand individuals in the population per year.

carrying capacity

the maximum sustainable population for a species in an area.

death phase

the portion of the population growth curve of some organisms that shows the population declining.

death rate

the number of deaths per thousand individuals in the population per year.

deceleration phase

the part of the population growth curve in which the rate of population increase begins to decline.

demography

the study of human populations, their characteristics, and their changes.

density-dependent limiting factors

those limiting factors that become more severe as the size of the population increases.

dispersal

migration of organisms from a concentrated population into areas with lower population densities.

doubling time

to determine how much time is needed to double the population.

ecological footprint

the area of earth's productive land and water required to supply the resources that an individual or population demands as well as to absorb the wastes that the individual or population produces.

emigration

the movement out of ana rea that was once one's place of residence.

environmental resistance

the combination of all environmental influences that tend to keep the population stable.

exponential growth phase (log phase)

a period during population growth when the population increases at an ever-increasing rate.

extrinsic limiting factors

factors that limit the population size and come from outside the population.

gross national income

an index that measures the total goods and services generated within a country as well as income earned and sent home by citizens of the country who ate living in other countries

immigration

the movement to an area where one has not previously resided.

intrinsic limiting factors

factors that limit the population size that come from within the population.

K-strategists

organisms that typically reach a stable population as the population reaches carrying capacity

lag phase

the initial stage of population growth during which growth occurs very slowly

less-developed countries

countries of the world that typically have a per capita income of less than US $15,000

limiting factors

the primary condition of the environment that determines the population size of an organism.

more-developed countries

countries of the world that typically have a per capita income that exceeds US $15,000

mortality

the number of deaths per year

natality

the number of individuals added to the population through reproduction over a particular time period

population

a group of individuals of the same species occupying a given area

population density

the measure of how close organisms are to one another, generally expressed as the number of organisms per unit area.

population growth rate

the rate at which additional individuals are added to the population; the birth rate minus the death rate.

R-strategists

typically a small organism that has a short life span, produces a large number of offspring, and does not reach a carrying capacity

replacement fertility

the number of children per woman needed just to replace the parents.

sex ratio

comparison between the number of males and females in a population

sexual reproduction

the production of numerous seeds, but the seeds must land in appropriate soil conditions before they will germinate to produce a new individual

stable equilibrium phase

the phase in a population growth curve in which the birth rate and death rate become equal

standard of living

an abstract concept that attempts to quantify the quality of life of people. Several factors included in an analysis of the standard of living are: economic well-being, health conditions, and the ability to change one's status in society

survivorship curve

a graph that shows the proportion of individuals likely to survive at each age

total fertility rate

the number of children born per women per lifetime

zero population growth

the stabilized growth stage of human during which births equal deaths and equilibrium is reached