Vocabulary Vocabulary ReviewReview

Ch 19Ch 19

PopulationsPopulations

A group of organisms of the same species that live in a specific

geographical area and interbreed

Population

The number of individuals of the same species that live in a given unit

of area

Population density

In ecology, the pattern of

distribution of organisms in a

population

Dispersion

The number of births that occur

in a period of time in a given area

Birth rate

The number of deaths occurring

in a period of time

Death rate

The average length of time that

an individual is expected to live

Life expectancy

The classification of members of a

population into groups according to age or the

distribution of members of a

population in terms of age groups

Age structure

A graph of the mortality data of a

population; indicates the probability that

individuals will survive to any given

age

Survivorship curve

An expression of the increase in the

size of an organism or

population over a given period of

timeGrowth rate

The movement of an individual or

group into an area

Immigration

The movement of an individual or group out of an

area

Emigration

A model of population growth in

which a constant and unlimited

growth rate results in geometric increases in

population sizeExponential

model

An environmental factor that prevents

an organism or population from reaching its full

potential of distribution or

activityLimiting factor

A model of population growth that assumes that

finite resource levels limit

population growth

Logistic model

The largest population that an environment can support at any

given time

Carrying capacity

A variable that affects a

population regardless of the

population density, such as

climateDensity-

independent factor

A variable affected by the number of

organisms present in a given area

Density-dependent

factor

The crossing or mating of plants or animals with close

relatives

Inbreeding

A way of life in which people

obtain their food by hunting and gathering wild

animals and plants

Hunter-gatherer lifestyle

The change from a hunting and

gathering society to an agricultural

society that began about 10,000

years agoAgricultural revolution

A modern, industrialized country in which people are

generally better educated and healthier

and live longer than people in developing

countries do

Developed country

A country in which the society is less modern and less industrialized

and in which inhabitants are

generally poorer than they are in developed

countries

Developing country

The general pattern of demographic change from high birth and death rates to low

birth and death rates, as observed in the history of more-

developed countries

Demographic transition