Question 1

Which statement about density-independent factors is true?

Accepted Answer

A)  Davidson and Andrewartha's studies of thrips (Thrips imaginis) showed that density-independent factors play a major role in the annual fluctuations of abundance of this species. 
B)  Density-independent factors increase the size of populations when population size is low. 
C)  Density-independent factors decrease the size of populations when population size is high. 
D)  Food and habitat availability are density-independent factors that influence population size. 
A)  Davidson and Andrewartha's studies of thrips (Thrips imaginis) showed that density-independent factors play a major role in the annual fluctuations of abundance of this species. 
B)  Density-independent factors increase the size of populations when population size is low. 
C)  Density-independent factors decrease the size of populations when population size is high. 
D)  Food and habitat availability are density-independent factors that influence population size. A

Question 2

Which statement about logistic growth is false?

Accepted Answer

A)  The carrying capacity is the maximum population size that can be supported by the environment for one year. 
B)  At low densities, logistic growth is similar to exponential growth. 
C)  At the carrying capacity, there is no population growth in the logistic model. 
D)  Logistic growth of a population can be represented by an S-shaped curve. 
A)  The carrying capacity is the maximum population size that can be supported by the environment for one year. 
B)  At low densities, logistic growth is similar to exponential growth. 
C)  At the carrying capacity, there is no population growth in the logistic model. 
D)  Logistic growth of a population can be represented by an S-shaped curve. A

Question 3

A population of prickly pear cacti has 1,500 individuals with an intrinsic rate of increase (r) of 0.3. As the population gets close to its carrying capacity of 2,000 individuals, how will r change?

Accepted Answer

A)  r will be near 0. 
B)  r will be less than zero. 
C)  r will be slightly less than 0.3. 
D)  r will be slightly more than 0.3. 
A)  r will be near 0. 
B)  r will be less than zero. 
C)  r will be slightly less than 0.3. 
D)  r will be slightly more than 0.3. A

Question 4

Refer to the figure.
  Based on the figure, how long did it take willows to reach their carrying capacity in Australia?

Accepted Answer

A)  It never reached carrying capacity. 
B)  12 months 
C)  1.2 years 
D)  12 years 
A)  It never reached carrying capacity. 
B)  12 months 
C)  1.2 years 
D)  12 years

Question 5

Refer to the figure.
  Based on the figure, what year is the world population growth rates expected to be only 1%?

Accepted Answer

A)  1960 
B)  2000 
C)  2020 
D)  never 
A)  1960 
B)  2000 
C)  2020 
D)  never

Question 6

Which type of survivorship curve is seen most frequently in the wild?

Accepted Answer

A)  Type I (most individuals survive to old age) 
B)  Type II (constant rate of mortality throughout lifetime) 
C)  Type III (most individuals die young) 
D)  Type I and Type II are about equally common. 
A)  Type I (most individuals survive to old age) 
B)  Type II (constant rate of mortality throughout lifetime) 
C)  Type III (most individuals die young) 
D)  Type I and Type II are about equally common.

Question 7

Which statement about density-dependent or density-independent growth is true?

Accepted Answer

A)  A decrease in birth rate with increasing population size is a density-independent factor. 
B)  An increase in emigration rate with increasing population size is a density-dependent factor. 
C)  Only density-independent factors can regulate population size. 
D)  Density-independent factors do not have large effects on population size. 
A)  A decrease in birth rate with increasing population size is a density-independent factor. 
B)  An increase in emigration rate with increasing population size is a density-dependent factor. 
C)  Only density-independent factors can regulate population size. 
D)  Density-independent factors do not have large effects on population size.

Question 8

Refer to the figure.
  Use the figure to determine the point at which the population growth rate is maximized under the logistic model.

Accepted Answer

A)  The rate is maximized when N = K/2. 
B)  The rate is maximized when the population is extremely small. 
C)  The rate is maximized when K is reached. 
D)  The rate is maximized when K is surpassed. 
A)  The rate is maximized when N = K/2. 
B)  The rate is maximized when the population is extremely small. 
C)  The rate is maximized when K is reached. 
D)  The rate is maximized when K is surpassed.

Question 9

The maximum population size that can be supported indefinitely by the environment is

Accepted Answer

A)  carrying capacity. 
B)  ecological footprint. 
C)  logistic growth curve. 
D)  survivorship curve. 
A)  carrying capacity. 
B)  ecological footprint. 
C)  logistic growth curve. 
D)  survivorship curve.

Question 10

Davidson and Andrewartha's studies of thrips (Thrips imaginis) showed that

Accepted Answer

A)  annual fluctuations in population size could be predicted based on rainfall and temperature data. 
B)  annual fluctuations in population size were due primarily to density-dependent factors. 
C)  density-independent factors increase the size of populations when population size is low. 
D)  a fluctuation in weather altered birth rates but did not alter death rates. 
A)  annual fluctuations in population size could be predicted based on rainfall and temperature data. 
B)  annual fluctuations in population size were due primarily to density-dependent factors. 
C)  density-independent factors increase the size of populations when population size is low. 
D)  a fluctuation in weather altered birth rates but did not alter death rates.

Question 11

A population of Drosophila mauritiana reproduces in synchrony at discrete time periods every generation, and generations occur at two-week intervals. The current population size is 1,000, and its geometric population growth rate is 3.0 per generation. What will the expected size of the population be after six weeks?

Accepted Answer

A)  3,000 
B)  9,000 
C)  27,000 
D)  81,000 
A)  3,000 
B)  9,000 
C)  27,000 
D)  81,000

Question 12

Refer to the figure.
  The birth and death rates of a population of garter snakes were monitored over 11 years, during which time population density varied considerably. According to the figure, which statement about the populations is true?

Accepted Answer

A)  Density-independent factors are regulating population size. 
B)  At high population sizes, the death rate is higher than it is at low population sizes. 
C)  Birth rate declines at high population sizes. 
D)  Birth rates equal death rates. 
A)  Density-independent factors are regulating population size. 
B)  At high population sizes, the death rate is higher than it is at low population sizes. 
C)  Birth rate declines at high population sizes. 
D)  Birth rates equal death rates.

Question 13

Which of the following would not be an example of density-dependent factors regulating population size?

Accepted Answer

A)  The number of possible territories for robins is limited; thus when population sizes are high, a lower proportion of individuals can produce offspring. 
B)  In conditions of overcrowding, some desert pupfish living in ponds will emigrate to other ponds if given the opportunity. 
C)  Predation on mosquitofish is high, regardless of population size. 
D)  In conditions of high density, mice are more susceptible to mortality from heat stress. 
A)  The number of possible territories for robins is limited; thus when population sizes are high, a lower proportion of individuals can produce offspring. 
B)  In conditions of overcrowding, some desert pupfish living in ponds will emigrate to other ponds if given the opportunity. 
C)  Predation on mosquitofish is high, regardless of population size. 
D)  In conditions of high density, mice are more susceptible to mortality from heat stress.

Question 14

In comparing exponential and geometric growth, which statement is true?

Accepted Answer

A)  Lambda (?) can be calculated from r and is equivalent to the natural logarithm of r. 
B)  Lambda (?) can be calculated from r and is equivalent to "e" raised to the r power. 
C)  The multiplier r can be calculated from F1F1F1S1$\lambda$F1F1F10, and is equivalent to "e" raised to the F1F1F1S1$\lambda$F1F1F10 power. 
D)  The multiplier r is not used in estimating exponential or geometric growth. 
A)  Lambda (?) can be calculated from r and is equivalent to the natural logarithm of r. 
B)  Lambda (?) can be calculated from r and is equivalent to "e" raised to the r power. 
C)  The multiplier r can be calculated from F1F1F1S1$\lambda$F1F1F10, and is equivalent to "e" raised to the F1F1F1S1$\lambda$F1F1F10 power. 
D)  The multiplier r is not used in estimating exponential or geometric growth.

Question 15

A fictional animal, the tribble, reproduces in synchrony at regular intervals. When the logarithm of a particular tribble population was plotted against time, the result was a straight and increasing line. Which statement about the tribble population is false?

Accepted Answer

A)  The tribble population is increasing in size geometrically. 
B)  The F1F1F1S1$\lambda$F1F1F10 of the tribble population is constant and greater than 1. 
C)  If the actual population size were plotted against time, the result would be an increasing J-shaped curve. 
D)  r = 0. 
A)  The tribble population is increasing in size geometrically. 
B)  The F1F1F1S1$\lambda$F1F1F10 of the tribble population is constant and greater than 1. 
C)  If the actual population size were plotted against time, the result would be an increasing J-shaped curve. 
D)  r = 0.

Question 16

Species A is a nonreproductive age shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. In year 0, 340 individuals were tagged. In year 1, 288 individuals were still alive. In year 2, 250 individuals were alive. In year 3, 200 individuals remained. Based on this data, calculate:
(a) The survivorship (lx) for year 1
(b) The survivorship (lx) for year 3.

Accepted Answer

Question 17

Which population is likely to be increasing in size?

Accepted Answer

A)  A population with an r of -0.04 
B)  A population with a F1F1F1S1$\lambda$F1F1F10 of 1.3 
C)  A population with a F1F1F1S1$\lambda$F1F1F10 of 0.98 
D)  A population with a F1F1F1S1$\lambda$F1F1F10 of 0 
A)  A population with an r of -0.04 
B)  A population with a F1F1F1S1$\lambda$F1F1F10 of 1.3 
C)  A population with a F1F1F1S1$\lambda$F1F1F10 of 0.98 
D)  A population with a F1F1F1S1$\lambda$F1F1F10 of 0

Question 18

The logistic equation assumes that

Accepted Answer

A)  the per capita growth rate is a constant. 
B)  the per capita growth rate declines with increasing density. 
C)  populations will increase in size indefinitely. 
D)  r increases in a straight line as density increases. 
A)  the per capita growth rate is a constant. 
B)  the per capita growth rate declines with increasing density. 
C)  populations will increase in size indefinitely. 
D)  r increases in a straight line as density increases.

Question 19

Mountain gorillas put a lot of effort in raising their young, ensuring they are protected and well cared for. In a natural population in the absence of poaching, and a lack of habitat destruction and other manmade dangers, the mountain gorilla would represent which type of survivorship curve?

Accepted Answer

A)  Type I 
B)  Type II 
C)  Type III 
D)  Type IV 
A)  Type I 
B)  Type II 
C)  Type III 
D)  Type IV

Question 20

A continuously growing population of alligators has a population size of 1,000 and an intrinsic rate of increase of r = 0.05 per year. Assuming that this rate of increase remains the same, about how long should it take for the population to grow larger than 4,000 individuals? (Note: The natural logarithm of 2 is about 0.70.)

Accepted Answer

A)  Less than 4 years 
B)  A little more than 7 years 
C)  About 14 years 
D)  A little more than 27 years 
A)  Less than 4 years 
B)  A little more than 7 years 
C)  About 14 years 
D)  A little more than 27 years

Exam 11: Population Growth and Regulation

Which statement about density-independent factors is true?

Which statement about logistic growth is false?

A population of prickly pear cacti has 1,500 individuals with an intrinsic rate of increase (r) of 0.3. As the population gets close to its carrying capacity of 2,000 individuals, how will r change?

Refer to the figure. Based on the figure, how long did it take willows to reach their carrying capacity in Australia?

Refer to the figure. Based on the figure, what year is the world population growth rates expected to be only 1%?

Which type of survivorship curve is seen most frequently in the wild?

Which statement about density-dependent or density-independent growth is true?

Refer to the figure. Use the figure to determine the point at which the population growth rate is maximized under the logistic model.

The maximum population size that can be supported indefinitely by the environment is

Davidson and Andrewartha's studies of thrips (Thrips imaginis) showed that

Refer to the figure. The birth and death rates of a population of garter snakes were monitored over 11 years, during which time population density varied considerably. According to the figure, which statement about the populations is true?

Which of the following would not be an example of density-dependent factors regulating population size?

In comparing exponential and geometric growth, which statement is true?

A fictional animal, the tribble, reproduces in synchrony at regular intervals. When the logarithm of a particular tribble population was plotted against time, the result was a straight and increasing line. Which statement about the tribble population is false?

Which population is likely to be increasing in size?

The logistic equation assumes that

Mountain gorillas put a lot of effort in raising their young, ensuring they are protected and well cared for. In a natural population in the absence of poaching, and a lack of habitat destruction and other manmade dangers, the mountain gorilla would represent which type of survivorship curve?

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