Ch 8 and 9 Review. All the members of a species living in the same place at the same time. population.

ENVIRONMENTAL Ch 8 and 9 Review

All the members of a species living in the same place at the same time.

population

The number of individuals per unit area or volume.

A populations’ density

The relative distribution or arrangement of its individuals within a given amount of space.

dispersion

How do scientists use properties such as size, density, and dispersion when referring to populations?

To predict changes within them

How does a population gain or lose individuals?

Birth, death, emigration, and immigration

A change in the size of a population over a given period of time.

Growth rate

How can the growth rate for a population be zero?

The number of births must equal the number of deaths.

What does it mean to say that a populations’ growth rate is negative?

The population decreases

How can populations remain stable when some species are capable of producing thousands of offspring?

Various factors kill individuals before they can reproduce

The fastest rate at which a population can grow.

Biotic potential

The maximum number of offspring that each member of a population can produce.

Reproductive potential

In what 3 ways may reproductive potential increase?

1) when individuals produce more offspring at one time

2) reproduce more often 3) reproduce earlier

The average time that it takes a member of the population to reach the age when it reproduces.

Generation time

When in nature can exponential growth occur?

When populations have plenty of space and food. When they have little or no competition.

What limits population growth?

Limited resources Changes in the environment Increased competition

The maximum population that an ecosystem can support.

Carrying Capacity

A natural resource that limits the carrying capacity for a species.

Limiting resource

An area defended by one or more individuals against other individuals.

territory

The unique role of a species within an ecosystem.

niche

Where an organism lives.

habitat

What are the five major types of species interactions?

Competition, predation, parasitism, mutualism, commensalism

A relationship in which different individuals or populations attempt to use the same limited resource.

competition

When does niche restriction occur?

When each species uses less of the niche than it is capable of using.

An organism that feeds on another organism.

predator

The organism that is fed upon.

prey

An organism that lives in or on another organism and feeds on it.

parasite

A close relationship between two species in which each species provides a benefit to the other.

mutualism

A relationship in which one species benefits and the other species is neither harmed nor helped.

commensalism

If one species becomes extinct, and then soon after, another species becomes extinct, was their relationship most likely competition or predation?

Predation. One species consumed the other and then succumbed to extinction

Scientists do not all agree on the specific carrying capacity of Earth for humans. Why might this be difficult to determine?

Different amounts of land is used by different countries for the production of meats, vegetables, and grains. You also have to include aquatic farms, ponds, and indoor green houses.

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What determines how a species interaction is categorized?

Whether or not a species is benefited or harmed

The study of human populations.

Demography

Why do demographers study the size and makeup of populations of countries?

To make comparisons and predictions. Economic growth, social structure, job availability, resource management.

How do demographers group countries?

As developed or developing

What are 3 characteristics of a developed country?

Higher average incomes, slower population growth, diverse industrial economies

What are 3 characteristics of a developing country?

Lower average incomes, simple and agriculture based economies, rapid population growth

Why did the human population grow rapidly in the 1800’s?

Increases in food production Improvements in hygiene

The distribution of ages in a specific population at a certain time.

Age structure

A double sided bar graph used to analyze population age structure.

Population pyramid

Countries that have high rates of growth usually have more ________ people than ________ people.

Young, older

Countries that have slow growth or no growth usually have an _________ distribution of ages.

even

The percentage of members of a group that are likely to survive to any given age.

survivorship

What is the difference between a type I and type II survivorship curve?

Type I represents wealthy countries where people live to an old age. Type II represents poor countries where many children die.

The number of babies born each year per 1000 women in a population.

Fertility rate

The average number of children a woman gives birth to in her lifetime.

Total fertility rate

The movement of individuals between areas.

migration

The movement of individuals into an area.

immigration

The movement of individuals out of an area.

emigration

The average number of years members of a population are likely to live.

Life expectancy

Life expectancy is most affected by ____________.

Infant mortality

What affects infant health more than anything else?

Access to education, food, fuel, and clean water.

A model that describes how economic and social changes affect population growth rates.

Demographic transition

What is the first stage of the demographic transition?

preindustrial

What happened in the 1800’s that dramatically increased the human population by increasing the rate of survival but decreasing the birth rate?

The Industrial Revolution

What two factors are most clearly related to a decline in birth rates?

Increasing education and economic independence for women

The basic facilities and services that support a community, such as public water supplies, sewer lines, power plants, roads, schools, and hospitals.

Infrastructure

Populations that have high rates of growth may create ____________ problems.

environmental

What 3 resources are most critically affected by rapid growth?

Vegetation, water, land

What is the main source of fuel in poor countries?

wood

Why is water unsafe when a region lacks infrastructure?

The local water supply may be used for drinking, washing, and sewage disposal.

Land that can be used to grow crops.

Arable land.

The movement of people from rural areas to cities.

urbanization

Small communities around cities.

suburbia

The movement of people from cities to around cities that leads to traffic jams, inadequate infrastructure, and the reduction of land for farms and wildlife habitat.

Suburban sprawl

How have China, Thailand, and India attempted to reduce birth rates?

Public advertising, family planning programs, economic incentives, legal punishments.

Most demographers predict the medium growth rate and a world population of ________ in 2050.

9 billion