Question 1

Which statement about cattle egrets in the Americas is false?

Accepted Answer

A)  Its arrival in South America was the result of a jump dispersal event. 
B)  It continues to grow exponentially in Florida and other states in the southeastern United States. 
C)  Its current distribution includes virtually all of the United States (except for Hawaii and Alaska). 
D)  The patterns observed in the cattle egret are typical of species that disperse to new regions. 
A)  Its arrival in South America was the result of a jump dispersal event. 
B)  It continues to grow exponentially in Florida and other states in the southeastern United States. 
C)  Its current distribution includes virtually all of the United States (except for Hawaii and Alaska). 
D)  The patterns observed in the cattle egret are typical of species that disperse to new regions.

Question 2

Which of the following is a plausible consequence of delayed density dependence in a population that would otherwise have logistic growth?

Accepted Answer

A)  Increased environmental stochasticity 
B)  Heightened oscillations 
C)  Population cycles 
D)  Exponential growth 
A)  Increased environmental stochasticity 
B)  Heightened oscillations 
C)  Population cycles 
D)  Exponential growth

Question 3

In which organism can one best observe the phenomenon of population cycles?

Accepted Answer

A)  Collared lemmings in Greenland 
B)  Cattle egrets in Florida 
C)  The comb jelly, Mnemiopsis leidyi, in the Black Sea 
D)  The bordered white moth in German forests 
A)  Collared lemmings in Greenland 
B)  Cattle egrets in Florida 
C)  The comb jelly, Mnemiopsis leidyi, in the Black Sea 
D)  The bordered white moth in German forests

Question 4

A small population of 100 organisms is only able to contribute 25 offspring to the next generation, but during that time, 30 individuals in the population die. In the next iteration, the remaining 95 individuals generate only 20 offspring, but during that time, 30 individuals of the population die. The remaining 85 individuals generate only 15 offspring, but during that time, 30 individuals of the population die. Which of the following terms best describes what this population is experiencing?

Accepted Answer

A)  Ineffective population size 
B)  Negative exponential growth 
C)  Carrying capacity 
D)  Extinction vortex 
A)  Ineffective population size 
B)  Negative exponential growth 
C)  Carrying capacity 
D)  Extinction vortex

Question 5

Which of the following is most likely to lead to population cycles?

Accepted Answer

A)  Demographic stochasticity 
B)  Delayed density dependence 
C)  Habitat fragmentation 
D)  Logistic growth 
A)  Demographic stochasticity 
B)  Delayed density dependence 
C)  Habitat fragmentation 
D)  Logistic growth

Question 6

Which of the following statements about effective population size is true?

Accepted Answer

A)  It is the minimum number of organisms needed for a population to survive. 
B)  It is the number of individuals needed to maximize genetic diversity. 
C)  It is the maximum number of individuals an ecosystem can support. 
D)  It is the number of individuals that can contribute offspring to the next generation. 
A)  It is the minimum number of organisms needed for a population to survive. 
B)  It is the number of individuals needed to maximize genetic diversity. 
C)  It is the maximum number of individuals an ecosystem can support. 
D)  It is the number of individuals that can contribute offspring to the next generation.

Question 7

Which of the following would be least likely to cause the extinction of a population comprising 20 individuals within a single generation?

Accepted Answer

A)  A natural catastrophe 
B)  Environmental stochasticity 
C)  Demographic stochasticity 
D)  Allee effects 
A)  A natural catastrophe 
B)  Environmental stochasticity 
C)  Demographic stochasticity 
D)  Allee effects

Question 8

Which statement about Nicholson's experiments with blowflies is true?

Accepted Answer

A)  Population cycles occurred when adults had limited food and maggots had unlimited food. 
B)  Population cycles occurred when both maggots and adults had unlimited food. 
C)  Population cycles occurred when both maggots and adults had limited food. 
D)  Population cycles occurred when adults had unlimited food and maggots had limited food. 
A)  Population cycles occurred when adults had limited food and maggots had unlimited food. 
B)  Population cycles occurred when both maggots and adults had unlimited food. 
C)  Population cycles occurred when both maggots and adults had limited food. 
D)  Population cycles occurred when adults had unlimited food and maggots had limited food.

Question 9

Which event did not contribute to the recovery of the Black Sea during the 1990s?

Accepted Answer

A)  Reduction in eutrophication 
B)  The arrival of another comb jelly that ate Mnemiopsis 
C)  Changes in bottom-up control 
D)  Allee effects 
A)  Reduction in eutrophication 
B)  The arrival of another comb jelly that ate Mnemiopsis 
C)  Changes in bottom-up control 
D)  Allee effects

Question 10

Which statement about the Black Sea is false?

Accepted Answer

A)  Because it is nearly land-locked, it exchanges little of its water with other ocean waters. 
B)  Only the top layer (about a tenth of its average depth) contains oxygen. 
C)  Native predators regulate the sea comb population. 
D)  The state of its ecosystem improved between the early and late 1990s. 
A)  Because it is nearly land-locked, it exchanges little of its water with other ocean waters. 
B)  Only the top layer (about a tenth of its average depth) contains oxygen. 
C)  Native predators regulate the sea comb population. 
D)  The state of its ecosystem improved between the early and late 1990s.

Question 11

Which statement about genetic drift is false?

Accepted Answer

A)  It can rapidly reduce the genetic variability of small populations. 
B)  It is a process by which chance events influence which alleles are transmitted to the next generation. 
C)  It is an Allee effect. 
D)  It can cause harmful alleles to occur at high frequency. 
A)  It can rapidly reduce the genetic variability of small populations. 
B)  It is a process by which chance events influence which alleles are transmitted to the next generation. 
C)  It is an Allee effect. 
D)  It can cause harmful alleles to occur at high frequency.

Question 12

Due to their low density, females of a species of turtles have difficulty finding mates. As a result, the population's growth rate has been low, despite ample resources. This is an example of

Accepted Answer

A)  an Allee effect. 
B)  environmental stochasticity. 
C)  genetic drift. 
D)  isolation by distance. 
A)  an Allee effect. 
B)  environmental stochasticity. 
C)  genetic drift. 
D)  isolation by distance.

Question 13

During the 1950s and 1960s, the cattle egret was quickly colonizing Florida. What pattern of population growth best describes that of the cattle egret at that time?

Accepted Answer

A)  Deterministic stochasticity 
B)  Large, random fluctuations 
C)  Exponential growth 
D)  Logistic growth 
A)  Deterministic stochasticity 
B)  Large, random fluctuations 
C)  Exponential growth 
D)  Logistic growth

Question 14

A population of rodents contained 703 individuals at the end of March. During the month of April, 47 died, 17 were born, 57 immigrated, and 16 emigrated. What was the population size after those events?

Accepted Answer

A)  673 
B)  692 
C)  714 
D)  730 
A)  673 
B)  692 
C)  714 
D)  730

Question 15

Imagine a moose in Grand Teton National Park, Wyoming is wandering around in a field of flowers. As it walks, it crushes and kills several flowers that turn out to be the last of their kind, causing that species of flower to go extinct. What is this an example of?

Accepted Answer

A)  Extinction vortex 
B)  Genetic drift 
C)  Density dependent factor 
D)  Allee effects 
A)  Extinction vortex 
B)  Genetic drift 
C)  Density dependent factor 
D)  Allee effects

Question 16

Which of the following statements is a conclusion of Jones and Diamond's studies of extinction in bird populations in the Channel Islands?

Accepted Answer

A)  Larger populations are at less risk of going extinct than smaller ones are. 
B)  Genetic drift is the most important factor in determining extinction risk. 
C)  Genetic drift is not an important factor in determining extinction risk. 
D)  Demographic stochasticity is the most important factor in determining extinction risk. 
A)  Larger populations are at less risk of going extinct than smaller ones are. 
B)  Genetic drift is the most important factor in determining extinction risk. 
C)  Genetic drift is not an important factor in determining extinction risk. 
D)  Demographic stochasticity is the most important factor in determining extinction risk.

Question 17

Which of the following provides a clear demonstration of logistic growth?

Accepted Answer

A)  Sheep introduced to Tasmania 
B)  Blowflies in which the adults are given unlimited supplies of liver but maggots are given a limited supply 
C)  Most natural populations of lemmings 
D)  Cattle egrets in Florida 
A)  Sheep introduced to Tasmania 
B)  Blowflies in which the adults are given unlimited supplies of liver but maggots are given a limited supply 
C)  Most natural populations of lemmings 
D)  Cattle egrets in Florida

Question 18

Which statement about the Black Sea is false?

Accepted Answer

A)  Its waters are well oxygenated from the surface to the floor of the sea. 
B)  Because it is nearly land-locked, it exchanges little of its water with other ocean waters. 
C)  Native predators and parasites failed to regulate its sea comb population. 
D)  The state of its ecosystem improved between the early 1990s and the late 1990s. 
A)  Its waters are well oxygenated from the surface to the floor of the sea. 
B)  Because it is nearly land-locked, it exchanges little of its water with other ocean waters. 
C)  Native predators and parasites failed to regulate its sea comb population. 
D)  The state of its ecosystem improved between the early 1990s and the late 1990s.

Question 19

Which statement about the effects of the comb jelly, Mnemiopsis leidyi, on the Black Sea is false?

Accepted Answer

A)  At the peak of its outbreak in 1989, the biomass of this comb jelly was far greater than the world's entire annual commercial fish catch. 
B)  This comb jelly is a voracious predator of young fish and fish eggs. 
C)  By reducing the population sizes of zooplankton, this comb jelly indirectly caused phytoplankton population sizes to increase. 
D)  The comb jelly immigrated to the black sea naturally. 
A)  At the peak of its outbreak in 1989, the biomass of this comb jelly was far greater than the world's entire annual commercial fish catch. 
B)  This comb jelly is a voracious predator of young fish and fish eggs. 
C)  By reducing the population sizes of zooplankton, this comb jelly indirectly caused phytoplankton population sizes to increase. 
D)  The comb jelly immigrated to the black sea naturally.

Question 20

Refer to the figure.
 
- Based on the figure, which of the following most likely explains the rapid increase in zooplankton between 1996 and 1999?

Accepted Answer

A)  Rapid decrease in chlorophyll a 
B)  Rapid increase in anchovies 
C)  Rapid decrease in Mnemiopsis 
D)  Rapid increase in Mnemiopsis 
A)  Rapid decrease in chlorophyll a 
B)  Rapid increase in anchovies 
C)  Rapid decrease in Mnemiopsis 
D)  Rapid increase in Mnemiopsis

Exam 10: Population Dynamics

Which statement about cattle egrets in the Americas is false?

Which of the following is a plausible consequence of delayed density dependence in a population that would otherwise have logistic growth?

In which organism can one best observe the phenomenon of population cycles?

Which of the following is most likely to lead to population cycles?

Which of the following statements about effective population size is true?

Which of the following would be least likely to cause the extinction of a population comprising 20 individuals within a single generation?

Which statement about Nicholson's experiments with blowflies is true?

Which event did not contribute to the recovery of the Black Sea during the 1990s?

Which statement about the Black Sea is false?

Which statement about genetic drift is false?

Due to their low density, females of a species of turtles have difficulty finding mates. As a result, the population's growth rate has been low, despite ample resources. This is an example of

During the 1950s and 1960s, the cattle egret was quickly colonizing Florida. What pattern of population growth best describes that of the cattle egret at that time?

A population of rodents contained 703 individuals at the end of March. During the month of April, 47 died, 17 were born, 57 immigrated, and 16 emigrated. What was the population size after those events?

Imagine a moose in Grand Teton National Park, Wyoming is wandering around in a field of flowers. As it walks, it crushes and kills several flowers that turn out to be the last of their kind, causing that species of flower to go extinct. What is this an example of?

Which of the following statements is a conclusion of Jones and Diamond's studies of extinction in bird populations in the Channel Islands?

Which of the following provides a clear demonstration of logistic growth?

Which statement about the Black Sea is false?

Which statement about the effects of the comb jelly, Mnemiopsis leidyi, on the Black Sea is false?

Refer to the figure. - Based on the figure, which of the following most likely explains the rapid increase in zooplankton between 1996 and 1999?

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