Question 1

Which statement about keystone predators is true?

Accepted Answer

A)  They usually are abundant in number and/or have disproportionately high biomass. 
B)  They usually influence primary producers directly. 
C)  They usually influence primary producers indirectly. 
D)  They are the same as foundation species. 
A)  They usually are abundant in number and/or have disproportionately high biomass. 
B)  They usually influence primary producers directly. 
C)  They usually influence primary producers indirectly. 
D)  They are the same as foundation species.

Question 2

Refer to the tables.
   Suppose you are researching an ecological community in a new study area. You divide your study area into quadrats and sample one quadrat a day to determine the species that occupy the area and how many individuals of these species are present. Assume that by the end of your sampling efforts, you have identified all of the species that occur in the study area. Use the numbers of individuals from Table 1 and the number of species in Table 2 to graph the relationship between total individuals and total species identified during your sampling efforts (this will be referred to as Figure 1). Graph your data as a line graph.

Accepted Answer

The answer of Refer to the tables.
   Suppose...

Question 3

Which statement about the difference between a competitive network and a competitive hierarchy is true?

Accepted Answer

A)  A competitive network comprises more species than interaction networks. 
B)  In a competitive hierarchy, one species dominates the interaction; in an interaction network, no one species dominates the interaction. 
C)  The interactions are stronger in a competitive network than in interaction networks. 
D)  In a competitive hierarchy, indirect species interactions always buffer strong competition; in interaction networks, they do not. 
A)  A competitive network comprises more species than interaction networks. 
B)  In a competitive hierarchy, one species dominates the interaction; in an interaction network, no one species dominates the interaction. 
C)  The interactions are stronger in a competitive network than in interaction networks. 
D)  In a competitive hierarchy, indirect species interactions always buffer strong competition; in interaction networks, they do not.

Question 4

Which statement about the seagrass Posidonia oceanica is false?

Accepted Answer

A)  It has been likened to an underwater tree due to its long life. 
B)  It supports a multitude of species that use its vegetation as habitat. 
C)  It has a growth pattern that is similar to that of the invasive alga Caulerpa taxifolia. 
D)  Its abundance has declined in places where Caulerpa taxifolia has invaded. 
A)  It has been likened to an underwater tree due to its long life. 
B)  It supports a multitude of species that use its vegetation as habitat. 
C)  It has a growth pattern that is similar to that of the invasive alga Caulerpa taxifolia. 
D)  Its abundance has declined in places where Caulerpa taxifolia has invaded.

Question 5

Lions prey on animals such as zebras and wildebeest, which feed primarily on grasses. Thus, lions should be considered

Accepted Answer

A)  primary consumers. 
B)  herbivores. 
C)  secondary consumers. 
D)  tertiary consumers 
A)  primary consumers. 
B)  herbivores. 
C)  secondary consumers. 
D)  tertiary consumers

Question 6

Refer to the table.

Accepted Answer

A)  ‒[0.48 (ln 0.48) + 0.32 (ln 0.32) + 0.12 (ln 0.12)] 
B)  ‒[0.48 (ln 0.48) + 0.32 (ln 0.32) + 0.2 (ln 0.2)] 
C)  0.48 (ln 0.48) + 0.32 (ln 0.32) + 0.12 (ln 0.12) 
D)  0.48 (ln 0.48) + 0.32 (ln 0.32) + 0.2 (ln 0.2) 
A)  ‒[0.48 (ln 0.48) + 0.32 (ln 0.32) + 0.12 (ln 0.12)] 
B)  ‒[0.48 (ln 0.48) + 0.32 (ln 0.32) + 0.2 (ln 0.2)] 
C)  0.48 (ln 0.48) + 0.32 (ln 0.32) + 0.12 (ln 0.12) 
D)  0.48 (ln 0.48) + 0.32 (ln 0.32) + 0.2 (ln 0.2)

Question 7

Estimates show that oceans absorb about _______ of the atmospheric CO2.

Accepted Answer

A)  1% 
B)  10% 
C)  40% 
D)  48% 
A)  1% 
B)  10% 
C)  40% 
D)  48%

Question 8

Suppose two populations of Anolis lizards are of equal size at the beginning of an experiment. One population (the experimental group) is exposed to a predator (16 predatory lizards), and the other (the control) is not. The final size of the experimental population is 50, and the final size of the control population is 200. What is the per capita interaction strength of predatory lizards on Anolis lizards?

Accepted Answer

A)  ln (4/16) 
B)  ln (4/50) 
C)  ln (16/4) 
D)  ln (16/50) 
A)  ln (4/16) 
B)  ln (4/50) 
C)  ln (16/4) 
D)  ln (16/50)

Question 9

In their studies of a salt marsh community, Sally Hacker and colleagues found that removing _______ led to a(n) _______.

Accepted Answer

A)  Juncus; increase in the abundance of Iva 
B)  Iva; increase in the abundance of Juncus 
C)  Juncus; increase in the abundance of aphids through indirect effects 
D)  Juncus; decrease in the abundance of aphids through indirect effects 
A)  Juncus; increase in the abundance of Iva 
B)  Iva; increase in the abundance of Juncus 
C)  Juncus; increase in the abundance of aphids through indirect effects 
D)  Juncus; decrease in the abundance of aphids through indirect effects

Question 10

Refer to the figure.
  The figure is of a species accumulation curve, based on the studies of Hughes and colleagues. The orange line (indicated by the black arrow) represents the species accumulation curve for which community in the study?

Accepted Answer

A)  Plants in a temperate forest in Michigan 
B)  Human oral bacteria 
C)  Costa Rica moth species 
D)  East Amazonian soil bacteria 
A)  Plants in a temperate forest in Michigan 
B)  Human oral bacteria 
C)  Costa Rica moth species 
D)  East Amazonian soil bacteria

Question 11

The trophic facilitation phenomenon described by Hacker and colleagues involves direct interactions between two plant species in the form of _______, with indirect effects benefiting a(n) _______ of one of the plants.

Accepted Answer

A)  commensalism; parasite 
B)  commensalism; herbivore 
C)  commensalism; competitor 
D)  competition; parasite 
A)  commensalism; parasite 
B)  commensalism; herbivore 
C)  commensalism; competitor 
D)  competition; parasite

Question 12

What is the Shannon index value for an area in which only a single species is present?

Accepted Answer

A)  0 
B)  1 
C)  ‒1 
D)  Infinity 
A)  0 
B)  1 
C)  ‒1 
D)  Infinity

Question 13

Consider two tropical forests, each of which has 2,700 species. Both forests possess 2,500 of the same species, but 200 of the species are present in either one or the other tropical forest, but not both. This consideration is a measure of

Accepted Answer

A)  species richness. 
B)  species evenness. 
C)  species composition. 
D)  species diversity. 
A)  species richness. 
B)  species evenness. 
C)  species composition. 
D)  species diversity.

Question 14

What is the primary difference between interaction webs and food webs?

Accepted Answer

A)  Interaction webs include more trophic levels. 
B)  Interaction webs include fewer trophic levels. 
C)  Interaction webs do not consider primary producers, where food webs do. 
D)  Interaction webs include non-trophic interactions, where food webs do not. 
A)  Interaction webs include more trophic levels. 
B)  Interaction webs include fewer trophic levels. 
C)  Interaction webs do not consider primary producers, where food webs do. 
D)  Interaction webs include non-trophic interactions, where food webs do not.

Question 15

If a biologist wanted to study a hot spring community and were to sample the bacterial species causing its various colors, this would be an example of what type of subset?

Accepted Answer

A)  Taxonomic 
B)  Guild 
C)  Functional 
D)  None of the above 
A)  Taxonomic 
B)  Guild 
C)  Functional 
D)  None of the above

Question 16

Refer to the figure.
  
-According to the figure, species A is a(n)

Accepted Answer

A)  primary producer. 
B)  herbivore. 
C)  carnivore. 
D)  omnivore. 
A)  primary producer. 
B)  herbivore. 
C)  carnivore. 
D)  omnivore.

Question 17

Which statement about the studies by Mary Power and colleagues on California rivers is true?

Accepted Answer

A)  In drought years the number of trophic levels increased. 
B)  Species, such as the steelhead, that are keystone predators during normal years are minor players in the food web during drought years. 
C)  The alga Cladophora completely died out during droughts. 
D)  Species interactions remained constant despite changes in environmental conditions. 
A)  In drought years the number of trophic levels increased. 
B)  Species, such as the steelhead, that are keystone predators during normal years are minor players in the food web during drought years. 
C)  The alga Cladophora completely died out during droughts. 
D)  Species interactions remained constant despite changes in environmental conditions.

Question 18

The presence of a mutualist spider in a certain area improves the survival of an herbaceous shrub by reducing the impact of herbivorous insects. These spiders are preyed on by lizards, and lizards are eaten by birds. The removal of birds from the area would most likely have a(n) _______ effect on spiders and a(n) _______ effect on the plant.

Accepted Answer

A)  indirect positive; indirect positive 
B)  indirect negative; indirect positive 
C)  direct negative; direct negative 
D)  indirect negative; indirect negative 
A)  indirect positive; indirect positive 
B)  indirect negative; indirect positive 
C)  direct negative; direct negative 
D)  indirect negative; indirect negative

Question 19

In the study by Jennifer Hughes and colleagues, in which community did it appear that the species richness had been adequately sampled?

Accepted Answer

A)  A plant community from a forest in Michigan 
B)  East Amazonian soil bacteria 
C)  Human oral bacteria 
D)  Costa Rican moths 
A)  A plant community from a forest in Michigan 
B)  East Amazonian soil bacteria 
C)  Human oral bacteria 
D)  Costa Rican moths

Question 20

Refer to the tables.

Accepted Answer

A)  Community 1 > Community 2 > Community 3 
B)  Community 1 > Community 3 > Community 2 
C)  Community 2 > Community 1 > Community 3 
D)  Community 3 > Community 2 > Community 1 
A)  Community 1 > Community 2 > Community 3 
B)  Community 1 > Community 3 > Community 2 
C)  Community 2 > Community 1 > Community 3 
D)  Community 3 > Community 2 > Community 1

Exam 16: The Nature of Communities

Which statement about keystone predators is true?

Which statement about the difference between a competitive network and a competitive hierarchy is true?

Which statement about the seagrass Posidonia oceanica is false?

Lions prey on animals such as zebras and wildebeest, which feed primarily on grasses. Thus, lions should be considered

Refer to the table.

Estimates show that oceans absorb about _______ of the atmospheric CO2.

In their studies of a salt marsh community, Sally Hacker and colleagues found that removing _______ led to a(n) _______.

Refer to the figure. The figure is of a species accumulation curve, based on the studies of Hughes and colleagues. The orange line (indicated by the black arrow) represents the species accumulation curve for which community in the study?

The trophic facilitation phenomenon described by Hacker and colleagues involves direct interactions between two plant species in the form of _______, with indirect effects benefiting a(n) _______ of one of the plants.

What is the Shannon index value for an area in which only a single species is present?

Consider two tropical forests, each of which has 2,700 species. Both forests possess 2,500 of the same species, but 200 of the species are present in either one or the other tropical forest, but not both. This consideration is a measure of

What is the primary difference between interaction webs and food webs?

If a biologist wanted to study a hot spring community and were to sample the bacterial species causing its various colors, this would be an example of what type of subset?

Refer to the figure. -According to the figure, species A is a(n)

Which statement about the studies by Mary Power and colleagues on California rivers is true?

In the study by Jennifer Hughes and colleagues, in which community did it appear that the species richness had been adequately sampled?

Refer to the tables.

The Web of Life

The Physical Environment

The Biosphere

Coping With Environmental Variation:

Coping With Environmental Variation: Energy

Evolution and Ecology

Life History

Behavioral Ecology

Population Distribution and Abundance

Population Dynamics

Population Growth and Regulation

Predation

Parasitism

Competition

Mutualism and Commensalism

Change in Communities

Biogeography

Species Diversity in Communities

Production

Energy Flow and Food Webs

Nutrient Supply and Cycling

Conservation Biology

Landscape Ecology and Ecosystem Management

Global Ecology

Filters

Estimates show that oceans absorb about _______ of the atmospheric CO₂.

In their studies of a salt marsh community, Sally Hacker and colleagues found that removing _ led to a(n) _.

The trophic facilitation phenomenon described by Hacker and colleagues involves direct interactions between two plant species in the form of _, with indirect effects benefiting a(n) _ of one of the plants.