Question 1

Write an equation that describes a situation in which a population remains stable.

Accepted Answer

Birth + immigration = death + ...

Question 2

Parasites often kill their hosts, although they do not directly benefit from their hosts' death. Yet many ecologists believe that parasites may have beneficial effects on their host populations. Why?

Accepted Answer

Parasites tend to destroy weaker and les...

Question 3

Some predators feed preferentially on the most abundant prey. This is an example of ________ predation.

Accepted Answer

A)  density-dependent
B)  density-independent
C)  competitive
D)  exponential
E)  cyclical

Question 4

In a population of lemmings, a sudden freeze that caused many of the lemmings to die is an example of a:

Accepted Answer

A)  nonliving and density-independent factor.
B)  living and density-dependent factor.
C)  nonliving and density-dependent factor.
D)  living and density-independent factor.
E)  normal boom-and-bust cycle.

Question 5

What might cause a uniform population distribution?

Accepted Answer

A)  the need for a group to care for its offspring
B)  allelopathy (the release of chemicals by plants to inhibit the growth of other plants nearby) 
C)  localization of resources
D)  the need to find a mate
E)  scarce resources

Question 6

The United Nations estimates that by 2050, the world's population may reach over ________ billion and still be growing.

Accepted Answer

A)  7) 0
B)  9) 0
C)  12.4
D)  15.6
E)  20.5

Question 7

How does environmental resistance affect a population?

Accepted Answer

Environmental resist...

Question 8

The different species within an ecosystem that interact in various ways make up a(n) :

Accepted Answer

A)  population.
B)  community.
C)  trophic level.
D)  aggregation.
E)  ecotone.

Question 9

How does the environment limit population growth?

Accepted Answer

Competition, predation, limits...

Question 10

A population size will remain stable if:

Accepted Answer

A)  the number of births each year is constant and the birth rate is higher than the death rate.
B)  the population grows by a fixed percentage of its size each year.
C)  the rate of emigration is higher than the rate of immigration.
D)  the birth and death rates are equal, as are the rates of emigration and immigration.
E)  environmental resistance declines each year.

Question 11

Which of the following is an important density-independent factor limiting population size?

Accepted Answer

A)  predation
B)  weather
C)  environmental resistance
D)  competition
E)  quantity of food

Question 12

In the equation "population growth = r × N," the letter r stands for ________.

Accepted Answer

The answer of In the equation "population growth = r...

Question 13

In ________ competition, one organism uses social or chemical interactions to limit the access of other individuals to resources.

Accepted Answer

A)  contest
B)  scramble
C)  interspecific
D)  intramural
E)  social

Question 14

Americans use about ________ times as much energy as the world average.

Accepted Answer

A)  1) 5
B)  2
C)  5
D)  10
E)  20

Question 15

If the individuals of a species are very likely to live until old age, that species exhibits a(n) ________ survivorship curve.

Accepted Answer

A)  convex
B)  constant
C)  concave
D)  S-shaped
E)  declining

Question 16

A complex, interrelated network of organisms and the surrounding nonliving environment in a defined area is a(n) :

Accepted Answer

A)  community.
B)  ecosystem.
C)  population.
D)  biosphere.
E)  biome.

Question 17

Humans are classified as a late-loss population. True or False?

Accepted Answer

A) True 
 B)False

Question 18

In areas that have a stable population, the number of children born in a period of time is:

Accepted Answer

A)  increasing.
B)  decreasing.
C)  approximately equal to the number of adults.
D)  higher than the number of adults.
E)  lower than the number of adults.

Question 19

When a population has inhabited an area for a long time and the population size has stabilized because of space and food limitations:

Accepted Answer

A)  the carrying capacity of the area has been reached.
B)  density dependence is clearly not involved in the population growth.
C)  predation decreases.
D)  density-independent factors are involved.
E)  the environmental resistance declines.

Question 20

All members of a species that reside within an ecosystem make up a(n) :

Accepted Answer

A)  population.
B)  community.
C)  trophic level.
D)  aggregation.
E)  ecotone.

Exam 26: Population Growth and Regulation

Humans are classified as a late-loss population. True or False?

Correct AnswerverifiedShow Answer

Some predators feed preferentially on the most abundant prey. This is an example of ________ predation.

Correct AnswerverifiedShow Answer

When a population has inhabited an area for a long time and the population size has stabilized because of space and food limitations:

Correct AnswerverifiedShow Answer

How does the environment limit population growth?

Correct AnswerverifiedCompetition, predation, limits...View AnswerShow Answer

The United Nations estimates that by 2050, the world's population may reach over ________ billion and still be growing.

Correct AnswerverifiedShow Answer

A population size will remain stable if:

Correct AnswerverifiedShow Answer

All members of a species that reside within an ecosystem make up a(n) :

Correct AnswerverifiedShow Answer

If the individuals of a species are very likely to live until old age, that species exhibits a(n) ________ survivorship curve.

Correct AnswerverifiedShow Answer

In areas that have a stable population, the number of children born in a period of time is:

Correct AnswerverifiedShow Answer

In ________ competition, one organism uses social or chemical interactions to limit the access of other individuals to resources.

Correct AnswerverifiedShow Answer

Parasites often kill their hosts, although they do not directly benefit from their hosts' death. Yet many ecologists believe that parasites may have beneficial effects on their host populations. Why?

Correct AnswerverifiedParasites tend to destroy weaker and les...View AnswerShow Answer

Which of the following is an important density-independent factor limiting population size?

Correct AnswerverifiedShow Answer

In a population of lemmings, a sudden freeze that caused many of the lemmings to die is an example of a:

Correct AnswerverifiedShow Answer

In the equation "population growth = r × N," the letter r stands for ________.

Correct AnswerverifiedShow Answer

Americans use about ________ times as much energy as the world average.

Correct AnswerverifiedShow Answer

How does environmental resistance affect a population?

Correct AnswerverifiedEnvironmental resist...View AnswerShow Answer

Write an equation that describes a situation in which a population remains stable.

Correct AnswerverifiedBirth + immigration = death + ...View AnswerShow Answer

The different species within an ecosystem that interact in various ways make up a(n) :

Correct AnswerverifiedShow Answer

A complex, interrelated network of organisms and the surrounding nonliving environment in a defined area is a(n) :

Correct AnswerverifiedShow Answer

What might cause a uniform population distribution?

Correct AnswerverifiedShow Answer

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Competition, predation, limits...
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Parasites tend to destroy weaker and les...
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Environmental resist...
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Birth + immigration = death + ...
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