Question 1

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

Question 2

To determine the number of individuals added to a population during a given time, multiply the growth rate (r) by the

Accepted Answer

A)   biotic potential.
B)   environmental resistance.
C)   final population size.
D)   number of immigrants.
E)   original population size. E

Question 3

An effective parasite is one that kills its host quickly.

Accepted Answer

A) True 
 B)False  False

Question 4

An insect population grows exponentially until an early winter freeze kills almost all of the insects. The next spring, the population grows exponentially again. This type of population growth is called

Accepted Answer

A)   sustained cycling.
B)   S- curve growth.
C)   boom- and- bust cycles.
D)   density- dependent growth.
E)   density- independent growth.

Question 5

Predation is considered a density- dependent factor that controls the population size of prey species. Give two examples of predators acting in density- dependent ways in response to fluctuations in the size of prey populations.

Accepted Answer

The answer of Predation is considered a density- dependent factor...

Question 6

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

Accepted Answer

A)   Quantity of food
B)   Predation
C)   Weather
D)   Environmental resistance
E)   Competition

Question 7

At the start of a study, 200 spotted owls lived in an old- growth forest patch in western Oregon. During the next year, a biologist tracking the birds observed that 25 new birds hatched and 5 died. What was the growth rate (r) for this year?

Accepted Answer

A)   5
B)   200
C)   0.1
D)   25
E)   20

Question 8

Although social changes and increased access to contraceptives have caused a decrease in fertility rates in some less- developed countries, their rates are still above RLF.

Accepted Answer

A) True 
 B)False

Question 9

In a maple forest in the spring, the ground is often covered with young maple seedlings, which compete for light and nutrients. By fall, most of the seedlings have died, leaving only a few survivors. This is an example of
life history pattern.

Accepted Answer

The answer of In a maple forest in the spring,...

Question 10

Why has it been so hard to come up with an accurate measure of Earth's carrying capacity for humans?

Accepted Answer

The answer of Why has it been so hard to...

Question 11

Based on its population pyramid, this population

Accepted Answer

A)   has reached its carrying capacity.
B)   is remaining the same.
C)   is showing negative growth.
D)   is in a boom- and- bust cycle.
E)   is expanding, or rapidly growing.

Question 12

Competition among individual members of the same species is referred to as competition.

Accepted Answer

The answer of Competition among individual members of the same...

Question 13

What percentage of Earth's productive land is currently used by the human population for crops and livestock?

Accepted Answer

A)   20%
B)   90%
C)   40%
D)   55%
E)   75%

Question 14

Increased population densities and increased competition lead to increased emigration.

Accepted Answer

A) True 
 B)False

Question 15

Why do many non- native species, such as a prickly pear cactus brought to Australia from South America, rapidly become abundant when first introduced?

Accepted Answer

A)   The climate in the new site is more favorable than in its native site.
B)   The carrying capacity at the new site is higher than that at the native site.
C)   Non- native species increase their reproductive rate when introduced.
D)   Growth changes from an S- curve to a J- curve at the new site.
E)   There are fewer predators and parasites capable of attacking the non- native species in the new site.

Question 16

In a stable population with neither immigration nor emigration, the RLF is 1.0 (one child per woman).

Accepted Answer

A) True 
 B)False

Question 17

Why does a bacteria population have a higher biotic potential than a population of humans?

Accepted Answer

The answer of Why does a bacteria population have a...

Question 18

To support the world population at the same standard of living as we have in the United States would require times the resources that are available on Earth today.

Accepted Answer

A)   20
B)   1.5
C)   5
D)   10
E)   2

Question 19

When a population has inhabited an area for a long time and the population size has stabilized, then

Accepted Answer

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

Question 20

Prey, such as lemmings, may have a density- dependent effect on predator populations, such as those of the snowy owl, by enabling the predator to increase the number of its offspring at high prey densities.

Accepted Answer

A) True 
 B)False

Exam 27: Population Growth and Regulation

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

To determine the number of individuals added to a population during a given time, multiply the growth rate (r) by the

An effective parasite is one that kills its host quickly.

An insect population grows exponentially until an early winter freeze kills almost all of the insects. The next spring, the population grows exponentially again. This type of population growth is called

Predation is considered a density- dependent factor that controls the population size of prey species. Give two examples of predators acting in density- dependent ways in response to fluctuations in the size of prey populations.

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

At the start of a study, 200 spotted owls lived in an old- growth forest patch in western Oregon. During the next year, a biologist tracking the birds observed that 25 new birds hatched and 5 died. What was the growth rate (r) for this year?

Although social changes and increased access to contraceptives have caused a decrease in fertility rates in some less- developed countries, their rates are still above RLF.

In a maple forest in the spring, the ground is often covered with young maple seedlings, which compete for light and nutrients. By fall, most of the seedlings have died, leaving only a few survivors. This is an example of life history pattern.

Why has it been so hard to come up with an accurate measure of Earth's carrying capacity for humans?

Based on its population pyramid, this population

Competition among individual members of the same species is referred to as competition.

What percentage of Earth's productive land is currently used by the human population for crops and livestock?

Increased population densities and increased competition lead to increased emigration.

Why do many non- native species, such as a prickly pear cactus brought to Australia from South America, rapidly become abundant when first introduced?

In a stable population with neither immigration nor emigration, the RLF is 1.0 (one child per woman).

Why does a bacteria population have a higher biotic potential than a population of humans?

To support the world population at the same standard of living as we have in the United States would require times the resources that are available on Earth today.

When a population has inhabited an area for a long time and the population size has stabilized, then

Prey, such as lemmings, may have a density- dependent effect on predator populations, such as those of the snowy owl, by enabling the predator to increase the number of its offspring at high prey densities.