Question 1

What interactions exist between cellulose-digesting organisms in the gut of a termite and the termite?

Accepted Answer

A)  +/+ 
B)  +/o 
C)  +/- 
D)  o/o 
E)  -/- 
A)  +/+ 
B)  +/o 
C)  +/- 
D)  o/o 
E)  -/- A

Question 2

Which statement best describes the evolutionary significance of mutualism?

Accepted Answer

A)  Mutualism offers more biodiversity to a community. 
B)  Individuals partaking in a mutualistic relationship are more resistant to parasites. 
C)  Interaction increases the survival and reproductive rates of mutualistic species. 
D)  Mutualistic interaction lessens competition in communities where it is present. 
E)  Mutualistic relationships allow organisms to synthesize and use energy more efficiently. 
A)  Mutualism offers more biodiversity to a community. 
B)  Individuals partaking in a mutualistic relationship are more resistant to parasites. 
C)  Interaction increases the survival and reproductive rates of mutualistic species. 
D)  Mutualistic interaction lessens competition in communities where it is present. 
E)  Mutualistic relationships allow organisms to synthesize and use energy more efficiently. C

Question 3

Evidence shows that some grasses benefit from being grazed. Which of the following terms would best describe this plant-herbivore interaction?

Accepted Answer

A)  mutualism 
B)  commensalism 
C)  parasitism 
D)  competition 
E)  predation 
A)  mutualism 
B)  commensalism 
C)  parasitism 
D)  competition 
E)  predation A

Question 4

The 1988 Yellowstone National Park lodgepole pine forest fires were likely the result of

Accepted Answer

A)  overgrazing by elk. 
B)  infrequent rain episodes. 
C)  years of fire suppression by humans. 
D)  unextinguished campfires. 
E)  geysers. 
A)  overgrazing by elk. 
B)  infrequent rain episodes. 
C)  years of fire suppression by humans. 
D)  unextinguished campfires. 
E)  geysers.

Question 5

The feeding relationships among the species in a community determine the community's

Accepted Answer

A)  secondary succession. 
B)  ecological niche. 
C)  species richness. 
D)  species-area curve. 
E)  trophic structure. 
A)  secondary succession. 
B)  ecological niche. 
C)  species richness. 
D)  species-area curve. 
E)  trophic structure.

Question 6

Biomanipulation can best be described as

Accepted Answer

A)  removing many of the organisms at the next higher trophic level so that the struggling trophic level below can recover. 
B)  a means of reversing the effects of pollution by applying antidote chemicals that have a neutralizing effect on the community. 
C)  an example of how one would use the bottom-up model for community restoration. 
D)  adjusting the numbers of each of the trophic levels back to the numbers that they were before human disturbance. 
E)  monitoring and adjusting the nutrient and energy flow through a community with new technologies. 
A)  removing many of the organisms at the next higher trophic level so that the struggling trophic level below can recover. 
B)  a means of reversing the effects of pollution by applying antidote chemicals that have a neutralizing effect on the community. 
C)  an example of how one would use the bottom-up model for community restoration. 
D)  adjusting the numbers of each of the trophic levels back to the numbers that they were before human disturbance. 
E)  monitoring and adjusting the nutrient and energy flow through a community with new technologies.

Question 7

Which of the following studies would shed light on the mechanism of spread of H5N1 from Asia?

Accepted Answer

A)  Perform cloacal or saliva smears of migrating waterfowl to monitor whether any infected birds show up in Alaska. 
B)  Test fecal samples for H5N1 in Asian waterfowl that live near domestic poultry farms in Asia. 
C)  Test for the presence of H5N1 in poultry used for human consumption worldwide. 
D)  Locate and destroy birds infected with H5N1 in Asian open-air poultry markets. 
E)  Keep domestic and wild fowl from interacting with each other to minimize the probability that wild fowl could get infected and migrate out of Asia. 
A)  Perform cloacal or saliva smears of migrating waterfowl to monitor whether any infected birds show up in Alaska. 
B)  Test fecal samples for H5N1 in Asian waterfowl that live near domestic poultry farms in Asia. 
C)  Test for the presence of H5N1 in poultry used for human consumption worldwide. 
D)  Locate and destroy birds infected with H5N1 in Asian open-air poultry markets. 
E)  Keep domestic and wild fowl from interacting with each other to minimize the probability that wild fowl could get infected and migrate out of Asia.

Question 8

According to the competitive exclusion principle, two species cannot continue to occupy the same

Accepted Answer

A)  habitat. 
B)  niche. 
C)  territory. 
D)  range. 
E)  biome. 
A)  habitat. 
B)  niche. 
C)  territory. 
D)  range. 
E)  biome.

Question 9

According to the nonequilibrium model,

Accepted Answer

A)  communities will remain in a climax state if there are no human disturbances. 
B)  community structure remains stable in the absence of interspecific competition. 
C)  communities are assemblages of closely linked species that are irreparably changed by disturbance. 
D)  interspecific interactions induce changes in community composition over time. 
E)  communities are constantly changing after being influenced by disturbances. 
A)  communities will remain in a climax state if there are no human disturbances. 
B)  community structure remains stable in the absence of interspecific competition. 
C)  communities are assemblages of closely linked species that are irreparably changed by disturbance. 
D)  interspecific interactions induce changes in community composition over time. 
E)  communities are constantly changing after being influenced by disturbances.

Question 10

In terms of community ecology, why are pathogens often more virulent now than before?

Accepted Answer

A)  More new pathogens have recently evolved. 
B)  Host organisms have become more susceptible because of weakened immune systems. 
C)  Human activities are transporting pathogens into new habitats (or communities) at an unprecedented rate. 
D)  Medicines for treating pathogenic disease are in short supply. 
E)  Sequencing of genes in pathogenic organisms is particularly difficult. 
A)  More new pathogens have recently evolved. 
B)  Host organisms have become more susceptible because of weakened immune systems. 
C)  Human activities are transporting pathogens into new habitats (or communities) at an unprecedented rate. 
D)  Medicines for treating pathogenic disease are in short supply. 
E)  Sequencing of genes in pathogenic organisms is particularly difficult.

Question 11

Resource partitioning would be most likely to occur between

Accepted Answer

A)  sympatric populations of a predator and its prey. 
B)  sympatric populations of species with similar ecological niches. 
C)  sympatric populations of a flowering plant and its specialized insect pollinator. 
D)  allopatric populations of the same animal species. 
E)  allopatric populations of species with similar ecological niches. 
A)  sympatric populations of a predator and its prey. 
B)  sympatric populations of species with similar ecological niches. 
C)  sympatric populations of a flowering plant and its specialized insect pollinator. 
D)  allopatric populations of the same animal species. 
E)  allopatric populations of species with similar ecological niches.

Question 12

Which of the following studies would a community ecologist undertake to learn about competitive interactions?

Accepted Answer

A)  selectivity of nest sites among cavity-nesting songbirds 
B)  the grass species preferred by grazing pronghorn antelope and bison 
C)  nitrate and phosphate uptake by various hardwood forest tree species 
D)  stomach analysis of brown trout and brook trout in streams where they coexist 
E)  all of the above 
A)  selectivity of nest sites among cavity-nesting songbirds 
B)  the grass species preferred by grazing pronghorn antelope and bison 
C)  nitrate and phosphate uptake by various hardwood forest tree species 
D)  stomach analysis of brown trout and brook trout in streams where they coexist 
E)  all of the above

Question 13

Which of the following best describes the consequences of white-band disease in Caribbean coral reefs?

Accepted Answer

A)  Staghorn coral has been decimated by the pathogen, and Elkhorn coral has taken its place. 
B)  Key habitat for lobsters, snappers, and other reef fishes has improved. 
C)  Algal species take the place of the dead coral, and the fish community is dominated by herbivores. 
D)  Algal species take over and the overall reef diversity increases due to increases in primary productivity. 
E)  Other coral species take the place of the affected Staghorn and Elkhorn species. 
A)  Staghorn coral has been decimated by the pathogen, and Elkhorn coral has taken its place. 
B)  Key habitat for lobsters, snappers, and other reef fishes has improved. 
C)  Algal species take the place of the dead coral, and the fish community is dominated by herbivores. 
D)  Algal species take over and the overall reef diversity increases due to increases in primary productivity. 
E)  Other coral species take the place of the affected Staghorn and Elkhorn species.

Question 14

Why are food chains relatively short?

Accepted Answer

A)  Top-level feeders tend to be more numerous than lower-trophic-level species. 
B)  Top-level feeders tend to be small but are capable of conserving more energy. 
C)  Longer chains are less stable and energy transfer between trophic levels is inefficient. 
D)  There are only so many organisms that are adapted to feed on other types of organisms. 
E)  Food chain length is ultimately determined by the photosynthetic efficiency of producers. 
A)  Top-level feeders tend to be more numerous than lower-trophic-level species. 
B)  Top-level feeders tend to be small but are capable of conserving more energy. 
C)  Longer chains are less stable and energy transfer between trophic levels is inefficient. 
D)  There are only so many organisms that are adapted to feed on other types of organisms. 
E)  Food chain length is ultimately determined by the photosynthetic efficiency of producers.

Question 15

Which of the following terms is used by ecologists to describe the community interaction where one organism makes the environment more suitable for another organism?

Accepted Answer

A)  parasitism 
B)  mutualism 
C)  inhibition 
D)  facilitation 
E)  commensalism 
A)  parasitism 
B)  mutualism 
C)  inhibition 
D)  facilitation 
E)  commensalism

Question 16

How might an ecologist test whether a species is occupying all of its fundamental niche or only a portion of it?

Accepted Answer

A)  Study the temperature range and humidity requirements of the species. 
B)  Observe if the niche size changes after the addition of nutritional resources to the habitat. 
C)  Observe if the niche size changes after the introduction of a similar non-native species. 
D)  Measure the change in reproductive success when the species is subjected to environmental stress. 
E)  Observe if the species expands its range after the removal of a competitor. 
A)  Study the temperature range and humidity requirements of the species. 
B)  Observe if the niche size changes after the addition of nutritional resources to the habitat. 
C)  Observe if the niche size changes after the introduction of a similar non-native species. 
D)  Measure the change in reproductive success when the species is subjected to environmental stress. 
E)  Observe if the species expands its range after the removal of a competitor.

Question 17

Based on the intermediate disturbance hypothesis, a community's species diversity is increased by

Accepted Answer

A)  frequent massive disturbance. 
B)  stable conditions with no disturbance. 
C)  moderate levels of disturbance. 
D)  human intervention to eliminate disturbance. 
E)  intensive disturbance by humans. 
A)  frequent massive disturbance. 
B)  stable conditions with no disturbance. 
C)  moderate levels of disturbance. 
D)  human intervention to eliminate disturbance. 
E)  intensive disturbance by humans.

Question 18

There are more species in tropical areas than in places more distant from the equator. This is probably a result of

Accepted Answer

A)  fewer predators. 
B)  more intense annual solar radiation. 
C)  more frequent ecological disturbances. 
D)  fewer agents of disease. 
E)  fewer predators, more intense annual solar radiation, more frequent ecological disturbances, and fewer agents of disease. 
A)  fewer predators. 
B)  more intense annual solar radiation. 
C)  more frequent ecological disturbances. 
D)  fewer agents of disease. 
E)  fewer predators, more intense annual solar radiation, more frequent ecological disturbances, and fewer agents of disease.

Question 19

Why do moderate levels of disturbance result in an increase in community diversity?

Accepted Answer

A)  Habitats are opened up for less competitive species. 
B)  Competitively dominant species infrequently exclude less competitive species after a moderate disturbance. 
C)  The environmental conditions become optimal. 
D)  The resulting uniform habitat supports stability, which in turn supports diversity. 
E)  Less-competitive species evolve strategies to compete with dominant species. 
A)  Habitats are opened up for less competitive species. 
B)  Competitively dominant species infrequently exclude less competitive species after a moderate disturbance. 
C)  The environmental conditions become optimal. 
D)  The resulting uniform habitat supports stability, which in turn supports diversity. 
E)  Less-competitive species evolve strategies to compete with dominant species.

Question 20

Elephants are not the most dominant species in African grasslands, yet they influence community structure. The grasslands contain scattered woody plants, but they are kept in check by the uprooting activities of the elephants. Take away the elephants, and the grasslands convert to forests or to shrublands. The newly growing forests support fewer species than the previous grasslands. Which of the following describes why elephants are the keystone species in this scenario?

Accepted Answer

A)  Elephants exhibit a disproportionate influence on the structure of the community relative to their abundance. 
B)  Grazing animals depend upon the elephants to convert forests to grassland. 
C)  Elephants prevent drought in African grasslands. 
D)  Elephants are the biggest herbivore in this community. 
E)  Elephants help other populations survive by keeping out many of the large African predators. 
A)  Elephants exhibit a disproportionate influence on the structure of the community relative to their abundance. 
B)  Grazing animals depend upon the elephants to convert forests to grassland. 
C)  Elephants prevent drought in African grasslands. 
D)  Elephants are the biggest herbivore in this community. 
E)  Elephants help other populations survive by keeping out many of the large African predators.

Exam 41: Species Interactions

What interactions exist between cellulose-digesting organisms in the gut of a termite and the termite?

Which statement best describes the evolutionary significance of mutualism?

Evidence shows that some grasses benefit from being grazed. Which of the following terms would best describe this plant-herbivore interaction?

The 1988 Yellowstone National Park lodgepole pine forest fires were likely the result of

The feeding relationships among the species in a community determine the community's

Biomanipulation can best be described as

Which of the following studies would shed light on the mechanism of spread of H5N1 from Asia?

According to the competitive exclusion principle, two species cannot continue to occupy the same

According to the nonequilibrium model,

In terms of community ecology, why are pathogens often more virulent now than before?

Resource partitioning would be most likely to occur between

Which of the following studies would a community ecologist undertake to learn about competitive interactions?

Which of the following best describes the consequences of white-band disease in Caribbean coral reefs?

Why are food chains relatively short?

Which of the following terms is used by ecologists to describe the community interaction where one organism makes the environment more suitable for another organism?

How might an ecologist test whether a species is occupying all of its fundamental niche or only a portion of it?

Based on the intermediate disturbance hypothesis, a community's species diversity is increased by

There are more species in tropical areas than in places more distant from the equator. This is probably a result of

Why do moderate levels of disturbance result in an increase in community diversity?

Introduction: Evolution and the Foundations of Biology

The Chemical Context of Life

Carbon and the Molecular Diversity of Life

A Tour of the Cell

Membrane Transport and Cell Signaling

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Development, Stem Cells, and Cancer

Viruses

Genomes and Their Evolution

Descent With Modification

Phylogeny

The Evolution of Populations

The Origin of Species

Broad Patterns of Evolution

Early Life and the Diversification of Prokaryotes

The Origin and Diversification of Eukaryotes

The Colonization of Land by Plants and Fungi

The Rise of Animal Diversity

Plant Structure and Growth

Resource Acquisition, Nutrition, and Transport in Vascular Plants

Reproduction and Domestication of Flowering Plants

Plant Responses to Internal and External Signals

Homeostasis and Endocrine Signaling

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Reproduction and Development

Neurons, Synapses, and Signaling

Nervous and Sensory Systems

Motor Mechanisms and Behavior

Population Ecology and the Distribution of Organisms

Ecosystems and Energy

Global Ecology and Conservation Biology

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