Ch. 18: Populations

Select all of the characteristics of populations that display type III survivorship.

-little parental investment -a high probability of death very early in life -many offspring

Select the two types of areas that typically have the highest human population densities.

-major river valleys -coastlines

Select all of the following that can contribute to a declining population size.

-migration out of the population -deaths outnumber births

Select all the characteristics of equilibrium species.

-provide much parental care -produce few offspring -long-lived

Select all the characteristics of opportunistic species.

-short-lived -have many offspring -reproduce at early age (NOT: much parental care provided Reason: This would be characteristic of equilibrium species. offspring mature at a late age Reason: This would be characteristic of equilibrium species.)

Which animal represents a population displaying a type I survivorship pattern?

Elephant (Insects typically exhibit a type III survivorship curve.)

Population dynamics must consider the number of individuals that are lost per unit of time, also called the

death rate.

If you were to look at the age structure of a population of an endangered species and determine that there are mostly older individuals you could say that the population is

declining and could be in danger of extinction.

The graph in the image shows

an age structure diagram. (Age structure includes all age classes at each successive year.)

The all inclusive portion of Earth where life exists is called the

biosphere.

In a population, the number of new individuals produced per individual in a defined time period is called the

birth rate.

This figure represents the ______ of human populations.

demographic transition

True or false: Species that have large numbers of offspring and show little to no parental care have an equilibrium (K-selected) life history.

false (Species that have large numbers of offspring and show little parental care have an opportunistic (r-selected) life history.)

In countries where economic development has substantially progressed, ______ are likely to be the major factors in declining birth rates.

family planning programs and women's education

In ______ growth, early rapid growth of a population eventually slows as the population approaches the carrying capacity of its habitat.

logistic

This figure represents ______ population growth.

logistic (Exponential growth is a J-shaped curve that doesn't flatten out and doesn't reach a carrying capacity.)

Swimming, flying, or walking into a population are active forms of ______, which is the movement of individuals between populations. Wind and water currents might also move individuals into a population.

migration

The birth rate of a population is the number of

new individuals produced per unit of time

In population dynamics, the death rate is the

number of deaths per unit of time

Number of offspring per reproductive episode and age at first reproduction affect

number of offspring an individual produces over its lifetime.

Besides growth, maintenance, and basic survival, ______ is an extremely costly demand on the energy resources of an organism.

reproduction

Life history biologists mainly research adaptations that influence an organism's

reproductive success.

Scientists who follow the number of individuals in an age group that are still alive at five-year intervals are studying ______ in a population.

survivorship

This figure shows a(n)

survivorship curve.

The age structure of a population is

the number of individuals in each age class.

A habitat is

the physical location where a population of organisms lives.

Birth rates are low in the ______ stage of the demographic transition.

third (Birth rates are mostly still high in the second stage. Birth rates are high in the first stage.)

The biosphere is

all the area on Earth where life exists.

Select all of the examples of density-dependent factors that limit population size.

-A population of bobcats is reduced due to lack of prey. -A deer population loses a significant number of individuals due to spread of an infectious disease among members of a population.

Identify species that have an equilibrium life history.

-Bears -Humans -Many birds

Select the two countries in which one-third of the Earth's human population live.

-China -India

Select all the reasons why measuring a population's density is useful.

-It helps establish hunting regulations. -It helps determine where to build human structures.

Select all of the following that correctly describe human population growth.

-It is characterized by an exponential growth pattern over the last 2,000 years. -The growth rate is declining, but is still above 0%, meaning the human population size is still growing. (The growth rate is still a positive value, and with such a large population size, even a small growth rate, such as 1.0%, produces overall population growth.)

Match each ecological level with its correct definition.

-Population : group of interbreeding organisms of the same species in one location at the same time -Community : all of the populations of multiple species in a given area -Ecosystem : all of the populations of multiple species in a given area plus the nonliving part of an environment, such as air, water, and minerals

Match the appropriate level of ecology to the example provided.

-Population : group of large-mouth bass in a local reservoir -Community : bass, sunfish, aquatic vegetation, and algae in a local reservoir -Ecosystem : soil, water, nutrients, and organisms in a local reservoir (A community includes all of the populations of multiple species living in a given area.)

Select the factors that can affect the number of offspring an individual can produce over its lifetime.

-The age of first reproduction. -The number of times it reproduces. -The number of offspring per reproductive episode.

Select all of the following that describe the population age structure of a growing human population.

-an age structure graph with the widest part at the base -high number of individuals entering the reproductive years

Select all the density-dependent factors that can limit population size.

-competition for mates -exposure to individuals infected with disease -competition with other species for resources -biotic factors (Density-independent: ~natural disasters ~habitat destruction by humans)

Select all of the following that are true of the world's wealthiest countries.

-currently consume more energy than less-developed countries -make up less than 20% of world's population

Match the stage of demographic transition with the correct explanation.

-first stage : little population growth; high birth and death rates -second stage : high birth rates and low death rates due to increases in technology and medical innovation; most less-developed countries are in this stage -third stage : low birth and death rates; more-developed countries are in this stage

Select all of the density-independent factors that can affect the size of populations.

-floods -lava flows -oil spills -habitat destruction due to human activities -fires

Select all of the characteristics of logistic growth.

-fluctuation around a carrying capacity -limited growth at high population size

A population has an equal birth and death rate but has more individuals migrating out than migrating in. How does the population change over time?

It decreases in size

Why does life history often reflect trade-offs that involve reproduction?

Reproduction takes a large amount of energy.

What is likely to be true in a population that is growing?

The birth rate is higher than the death rate.

True or false: The human population has been growing exponentially.

True (The curve is J-shaped)

In terms of age structure, what country is considered to be in the "growing" category?

Uganda (NOT: China is actually declining.)

In the list below, what country has the largest ecological footprint?

United States

As economic development of a country increases, the availability of family planning, education of women, and increased opportunities for women outside the home all contribute to

a decline in birth rates.

The numbers of individuals in different age classes of a population is called the population's

age structure.

An aquarium houses a stable population of about 4,000 rotifers. A population size of 4,000 is the

carrying capacity of the aquarium for the rotifers.

The maximum number of individuals a habitat can support is called the

carrying capacity.

Population ________ is the number of individuals of a species per unit of area or unit of volume of habitat.

density (Population dynamics focuses on the factors that affect change in a population size. Population distribution describes how individuals are scattered through habitat space. It does not count the individuals per area of the space.)

If a population's size is limited based on factors that are associated with more individuals in the population coming into close contact with one another, those factors are

density-dependent.

Factors that affect population growth and are unrelated to the density of the population are called

density-independent factors.

The measure of the amount of land area needed to support a country's overall lifestyle is a(n) _____ footprint.

ecological

The land area required to support a country at its particular lifestyle is called the

ecological footprint

The study of the relationships among organisms and the environment is called

ecology

Ecology is the study of relationships among organisms and their

environment.

If there are more children than parents in a population, the population as a whole will tend to ______ over time.

grow

A population in the exponential growth phase

grows faster the larger the population size

A hardwood forest is a squirrel population's ______, the physical location where the population of a certain species lives.

habitat

A population of sunfish live in a lake. In ecology, that lake is classified as a

habitat.

The physical location where the members of a population normally live is called the

habitat.

The graph shows that after about 35 days, the population

has reached the carrying capacity.

Exponential growth curves

have a J shape.

The population with the highest density would

have a large number of individuals in a small area

Abiotic factors such as natural disasters are examples of density-_____ factors limiting population growth.

independent

In the demographic transition, a population's birth rate

is high at first, then transitions to low.

If a scientist is studying all of the events of an organism's life from conception to death that influence reproductive success, they are studying the ______ of that organism.

life history

This age structure diagram for a population of white oaks shows that the population is

likely to grow in the future.

To determine if conservation efforts are working, ecologists need to measure

population density over several months or years.