Question 1

What do the data in the graphs suggest about the resistance of the community to disturbance?

Accepted Answer

A)  Communities with any amount of plants are very resistant to disturbance. 
B)  Community resistance depends on whether herbivores, predators, and parasites are present. 
C)  Herbivore species richness and abundance both increase with small changes in plant species richness. 
D)  The stability of herbivore species richness and abundance respond independently of plant species richness. 
A)  Communities with any amount of plants are very resistant to disturbance. 
B)  Community resistance depends on whether herbivores, predators, and parasites are present. 
C)  Herbivore species richness and abundance both increase with small changes in plant species richness. 
D)  The stability of herbivore species richness and abundance respond independently of plant species richness.

Question 2

Which is an example of a trait-mediated indirect effect?

Accepted Answer

A)  A predator causes a consumer to change its foraging pattern, affecting the amount of food consumed. 
B)  Predators consume most of their main prey, then switch to omnivory. 
C)  Herbivores migrate in and out of communities depending on perceived predation risk. 
D)  Herbivores consume vegetation, which reduces hiding places for predators stalking their prey. 
A)  A predator causes a consumer to change its foraging pattern, affecting the amount of food consumed. 
B)  Predators consume most of their main prey, then switch to omnivory. 
C)  Herbivores migrate in and out of communities depending on perceived predation risk. 
D)  Herbivores consume vegetation, which reduces hiding places for predators stalking their prey.

Question 3

What is the difference between a food chain and food web?

Accepted Answer

A food chain is a linear pathw

Question 4

Carbon dioxide with radioactive carbon was bubbled into an illuminated aquarium containing unfiltered pond water. In what order will radioactivity appear in various organisms in the aquarium?

Accepted Answer

A)  herbivores, carnivores, producers 
B)  producers, herbivores, carnivores 
C)  producers, carnivores, herbivores 
D)  herbivores, producers, carnivores 
E)  All organisms will take up radioactive carbon simultaneously. 
A)  herbivores, carnivores, producers 
B)  producers, herbivores, carnivores 
C)  producers, carnivores, herbivores 
D)  herbivores, producers, carnivores 
E)  All organisms will take up radioactive carbon simultaneously.

Question 5

-The presence of fish has a positive effect on shoreline flowering plants. Which lines in the diagram reflect a negative direct effect?

Accepted Answer

A)  fish → adult dragonfly 
B)  fish → pollinator 
C)  fish → larval dragonfly 
D)  adult dragonfly → plants 
A)  fish → adult dragonfly 
B)  fish → pollinator 
C)  fish → larval dragonfly 
D)  adult dragonfly → plants

Question 6

-What most accurately describes a trophic cascade?

Accepted Answer

A)  bottom-up effects 
B)  top-down effects 
C)  found in waterfall habitats 
D)  is based on two trophic levels 
A)  bottom-up effects 
B)  top-down effects 
C)  found in waterfall habitats 
D)  is based on two trophic levels

Question 7

Which response variable (on the y axis) did not increase with plant species richness?

Accepted Answer

A)  stability of herbivore species richness 
B)  stability of herbivore abundance 
C)  stability of predator and parasite species richness 
D)  stability of predator and parasite abundance 
A)  stability of herbivore species richness 
B)  stability of herbivore abundance 
C)  stability of predator and parasite species richness 
D)  stability of predator and parasite abundance

Question 8

A researcher removed predatory starfish from sections of intertidal rock and found that the number of prey species decreased by 50 percent relative to control plots within a short time. This indicates: that

Accepted Answer

A)  predators compete with prey for space. 
B)  predator species are competing for prey. 
C)  starfish predation increases prey diversity. 
D)  starfish predation reduces prey diversity. 
A)  predators compete with prey for space. 
B)  predator species are competing for prey. 
C)  starfish predation increases prey diversity. 
D)  starfish predation reduces prey diversity.

Question 9

How would adding resources such as fertilizer to an area affect the species in a community?

Accepted Answer

A)  It would reduce richness. 
B)  It would increase richness. 
C)  It would increase the abundance of all species. 
D)  It would reduce the abundance of all species. 
A)  It would reduce richness. 
B)  It would increase richness. 
C)  It would increase the abundance of all species. 
D)  It would reduce the abundance of all species.

Question 10

Explain the relationships that appear to reduce tadpole abundance when insecticide is present, even though insecticide does not directly affect tadpoles.

Accepted Answer

Insecticide reduces zooplankton. Less zo

Question 11

How does an ecologist determine the presence of an ecotone?

Accepted Answer

A)  measure the abundance of plant species over space and abrupt changes in species composition 
B)  perform controlled crosses among all plant species within a community to determine the extent to which the species are reproductively isolated 
C)  measure microclimate and soil variables for abrupt changes 
D)  measure elevation, since many environmental and ecological variables change with elevation 
A)  measure the abundance of plant species over space and abrupt changes in species composition 
B)  perform controlled crosses among all plant species within a community to determine the extent to which the species are reproductively isolated 
C)  measure microclimate and soil variables for abrupt changes 
D)  measure elevation, since many environmental and ecological variables change with elevation

Question 12

Explain what the intermediate disturbance hypothesis predicts for the comparison of species richness in forests where fires have been suppressed versus those with unsuppressed natural fire.

Accepted Answer

The intermediate disturbance h

Question 13

Explain how the second law of thermodynamics limits the number of trophic levels in a food web.

Accepted Answer

The second law of thermodynamics include

Question 14

Use the figure to answer questions 4 to 7.
  
-Which species is restricted to the ecotone between serpentine and nonserpentine soils?

Accepted Answer

A)  black oak 
B)  hawkweed 
C)  ragwort 
D)  fireweed 
A)  black oak 
B)  hawkweed 
C)  ragwort 
D)  fireweed

Question 15

The graph suggests that

Accepted Answer

A)  plant survival rate is not affected by elevation. 
B)  plant survival rate is not affected by the presence or absence of a neighbouring species. 
C)  plant survival is dependent on the presence of a neighbouring species. 
D)  plant survival is independent of the presence of a neighbouring species. 
A)  plant survival rate is not affected by elevation. 
B)  plant survival rate is not affected by the presence or absence of a neighbouring species. 
C)  plant survival is dependent on the presence of a neighbouring species. 
D)  plant survival is independent of the presence of a neighbouring species.

Question 16

What, in addition to tolerance to soil characteristics, might account for the distribution of plant species over different soil types?

Accepted Answer

The distribution could be due to relativ

Question 17

Which is an example of an ecosystem engineer?

Accepted Answer

A)  beavers, which build dams on streams 
B)  termites, which build very large hives and eat the wood in buildings 
C)  bees, which pollinate many types of flowers and crops 
D)  zebra mussels, which clog water intake structures 
A)  beavers, which build dams on streams 
B)  termites, which build very large hives and eat the wood in buildings 
C)  bees, which pollinate many types of flowers and crops 
D)  zebra mussels, which clog water intake structures

Question 18

What community measure does Shannon's index quantify?

Accepted Answer

A)  the number of species 
B)  relative abundance of species 
C)  species richness 
D)  species diversity 
A)  the number of species 
B)  relative abundance of species 
C)  species richness 
D)  species diversity

Question 19

How would a relatively high proportion of omnivore species in a food web affect the connectedness of the food web?

Accepted Answer

Since omnivores can feed at mo

Question 20

How can predation increase prey species richness and evenness in a community?

Accepted Answer

Predators are likely to select the most

Exam 18: Community Structure

What do the data in the graphs suggest about the resistance of the community to disturbance?

Which is an example of a trait-mediated indirect effect?

What is the difference between a food chain and food web?

Carbon dioxide with radioactive carbon was bubbled into an illuminated aquarium containing unfiltered pond water. In what order will radioactivity appear in various organisms in the aquarium?

-The presence of fish has a positive effect on shoreline flowering plants. Which lines in the diagram reflect a negative direct effect?

-What most accurately describes a trophic cascade?

Which response variable (on the y axis) did not increase with plant species richness?

A researcher removed predatory starfish from sections of intertidal rock and found that the number of prey species decreased by 50 percent relative to control plots within a short time. This indicates: that

How would adding resources such as fertilizer to an area affect the species in a community?

Explain the relationships that appear to reduce tadpole abundance when insecticide is present, even though insecticide does not directly affect tadpoles.

How does an ecologist determine the presence of an ecotone?

Explain what the intermediate disturbance hypothesis predicts for the comparison of species richness in forests where fires have been suppressed versus those with unsuppressed natural fire.

Explain how the second law of thermodynamics limits the number of trophic levels in a food web.

Use the figure to answer questions 4 to 7. -Which species is restricted to the ecotone between serpentine and nonserpentine soils?

The graph suggests that

What, in addition to tolerance to soil characteristics, might account for the distribution of plant species over different soil types?

Which is an example of an ecosystem engineer?

What community measure does Shannon's index quantify?

How would a relatively high proportion of omnivore species in a food web affect the connectedness of the food web?

How can predation increase prey species richness and evenness in a community?

Introduction: Ecology, Evolution, and the Scientific Method

Adaptations to Aquatic Environments

Adaptations to Terrestrial Environments

Adaptations to Variable Environments

Climates and Soils

Terrestrial and Aquatic Biomes

Evolution and Adaptation

Life Histories

Reproductive Strategies

Social Behaviours

Population Distributions

Population Growth and Regulation

Population Dynamics Over Space and Time

Predation and Herbivory

Parasitism and Infectious Diseases

Competition

Community Succession

Movement of Energy in Ecosystems

Movement of Elements in Ecosystems

Landscape Ecology, Biogeography, and Global Biodiversity

Global Conservation of Biodiversity

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