Deck 33: Populations in Ecology

Question 1

What has been the effect of eliminating the natural predators on deer in the United States?

A) There has been no effect.
B) The deer population has dwindled.
C) The deer population has grown tremendously.
D) The deer population has plummeted.

Answer 1

The deer population has grown tremendously.

Question 2

For each of the scientific studies described in the questions that follow, choose the scale of the study.

-Egg production in Rana catesbeiana grown at different ambient temperatures

A) ecosystem
B) population
C) species
D) community

Answer 2

species

Question 3

For each of the scientific studies described in the questions that follow, choose the scale of the study.

-Understory herb abundances and species diversity in pine plantations under different management regimes in North Carolina

A) species
B) ecosystem
C) population
D) community

Answer 3

community

Question 4

For each of the scientific studies described in the questions that follow, choose the scale of the study.

-All of the individuals of Rana catesbeiana in a pond in central Massachusetts comprise a:

A) population.
B) guild.
C) biome.
D) caste.

Question 5

Exponential growth:

A) occurs when there are many environmental limits to reproduction.
B) is an S-shaped curve when plotted.
C) occurs when the population increases in proportion to the number of organisms in the population.
D) is never characteristic of an invading species.

Question 6

Logistic growth:

A) occurs when predators are very limited in population size.
B) describes the crash in a population when the environment runs out of food or habitat for a species.
C) describes the growth of a population in an environment with an unlimited carrying capacity.
D) is plotted as a J-shaped curve.

Question 7

Refer to the figure above and then answer the question that follows.

-The intrinsic rate of increase:

A) is the rate at which a population would grow if there were no external limits to growth.
B) is the death rate minus the birth rate, or a measure of annual population change in a population near K.
C) is the rate at which populations grow in nature in the face of all environmental limits.
D) will be 1 when the birth rate equals the death rate.

Question 8

Which statement is true about a population that is relatively undisturbed by humans?

A) It grows logistically with a carrying capacity that can change.
B) It grows exponentially with a carrying capacity that can change.
C) It grows logistically with a carrying capacity that is constant.
D) It grows arithmetically with a population limit.

Question 9

Exponential growth, experienced occasionally by populations of organisms, ________.

A) is possible only in less complex, lower-order organisms.
B) has no effect on the organisms' environment.
C) is a natural response that conserves resources.
D) is possible in many orders of life.

Question 10

Which of the following factors reduces the generation time of a human population?

A) more education
B) less education
C) better birth control
D) fewer reproductive adults

Question 11

If the population of mountain lions adds 10 new lions each year for 20 years, we would classify this type of growth as:

A) declining.
B) exponential.
C) arithmetic.
D) logarithmic.

Question 12

If a population of mountain lions adds new individuals equal to 5 percent of the population each year, we would classify this type of growth as:

A) increasing.
B) exponential.
C) arithmetic.
D) positive.

Question 13

What kind of growth would you expect from a species of clam that invades a large lake in which no clams live?

A) steady
B) exponential
C) arithmetic
D) positive

Question 14

If you subtract the death rate from the birth rate of a population, you will calculate:

A) the arithmetic growth rate.
B) the expansion rate.
C) the intrinsic growth rate.
D) the carrying capacity.

Question 15

Dandelions have a short life span and a high investment in seed production, but each seed is small and wind-dispersed. This is an example of:

A) a K-selected species.
B) an equilibrium species.
C) an r-selected species.
D) a density-dependent species.

Question 16

The human population is currently following a J-shaped curve. This means that the population is currently growing:

A) logistically.
B) sigmoidally.
C) exponentially.
D) arithmetically.

Question 17

Though thought of as an equilibrium species, humans currently exhibit growth patterns more common to:

A) G-selected species.
B) E-selected species.
C) K-selected species.
D) r-selected species.

Question 18

What can be said about K-selected species relative to the carrying capacity of their habitat?

A) They never approach the carrying capacity.
B) They never exceed the carrying capacity.
C) They always exceed the carrying capacity.
D) They sometimes exceed the carrying capacity.

Question 19

What seems to be the most influential factor in making possible the explosion in the human population that began around 1800?

A) more food production
B) the industrial revolution
C) conquering of diseases
D) genetic mutations

Question 20

Refer to the figure above and then answer the question that follows.

-In many developing countries, the population pyramid is broad at the base and narrow at the top. What does this indicate?

A) That growth is arithmetic.
B) That there are few, if any, density-dependent factors affecting population size.
C) That fertility is increasing.
D) That there are more young individuals than post-reproductive individuals.

Question 21

Which of the following is/are true?

A) Birth rates of cohorts are plotted by age on a population pyramid.
B) A population pyramid can show relative numbers of young versus post-reproductive individuals.
C) K can be determined from a population pyramid by subtracting the number in the top row from the number in the bottom row.
D) Both A and C are correct.

Question 22

Which is true?

A) The U.S. population will exceed 1.5 billion by the middle of the next century.
B) Immigration is not expected to have a large effect on the U.S. population in the next century.
C) The birth rate of the U.S. population is expected to be lower than the death rate by the middle of the next century.
D) Emigration is expected to have a large effect on the U.S. population in the next century.

Question 23

Human populations have shown a rapid growth increase in the last century because of:

A) the fertility revolution.
B) new birth control methods.
C) the industrial revolution.
D) the sexual revolution.

Question 24

Human populations have shown a rapid growth increase in the last century by increasing their:

A) biotic potential.
B) intrinsic rate of increase.
C) carrying capacity.
D) fertility rates.

Question 25

By the end of the twenty-first century, the human population is expected to be:

A) over 12.5 billion.
B) 3.5 to 5 billion.
C) 8.5 to 11 billion.
D) 10 to 12.5 billion.

Question 26

In less-developed countries, the population pyramid tends to be shaped like.

A) a rectangle.
B) a square.
C) an egg.
D) a pyramid.

Question 27

In more-developed countries, the population pyramid tends to be shaped like:

A) an inverted triangle.
B) an egg.
C) a pyramid.
D) a rectangle.

Question 28

The population of the United States continues to grow as a result of:

A) immigration.
B) increases in r.
C) an inverted triangular pyramid.
D) Both A and C are correct.

Question 29

It is possible to have a community that consists of a single species.

Question 30

An exponential increase in a population is the same as an arithmetic increase.

Question 31

An arithmetic growth curve will have a steeper upward slope than an exponential growth curve.

Question 32

The carrying capacity of a habitat can transform a J-shaped curve into an S-shaped curve.

Question 33

Most organisms in the real world follow an arithmetic growth pattern, rather than an exponential growth pattern.

Question 34

Environmental resistance can turn a J-shaped growth curve into an S-shaped growth curve.

Question 35

Most K-selected species are large and long-lived.

Question 36

During succession, there is a general trend toward increased species diversity.

Question 37

List at least three differences between an r-selected species and a K-selected species.

Question 38

Explain how you would calculate r for a population.

Question 39

Ecologists often say that one individual living in a developed country cannot be counted as ecologically equal to one individual from a developing country. Why?

Question 40

Draw a typical population pyramid for (a) a developed country and (b) a developing country.

Question 41

What are the three shapes of survivorship curves, and what does each one tell us about the population? Give an example of a species for each survivorship curve.