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Campbell Biology, 10e (Reece)
Chapter 54 Community Ecology
1) Some birds follow moving swarms of army ants in the tropics. As the ants march along the
forest floor hunting insects and small vertebrates, birds follow and pick off any insects or small
vertebrates that fly or jump out of the way of the ants. This situation is an example of what kind
of species interaction between the birds and the ants?
A) consumption
B) commensalism
C) parasitism
D) mutualism
2) In the hypothesis that C. stellatus (a species of barnacle) is competitively excluded from the
lower intertidal zone by B. balanoides (another species of barnacle), what could be concluded
about the two species?
A) The fundamental and realized niches of B. balanoides and C. stellatus are identical.
B) The fundamental and realized niches of B. balanoides and C. stellatus are different.
C) The fundamental and realized niches of B. balanoides are different, but the fundamental and
realized niches of C. stellatus are identical.
D) The fundamental and realized niches of B. balanoides are identical, but the fundamental and
realized niches of C. stellatus are different.
3) What conclusion can you draw from the figure above?
A) Without direct contact, mussels can sense the presence of crabs.
B) Mussels can sense the presence of crabs only visually.
C) Mussels are increasing their shell thickness in response to water current.
D) Crabs hunt for mussels by focusing on the chemicals they emit into the water.
4) As you study two closely related predatory insect species, the two-spot and the three-spot
avenger beetles, you notice that each species seeks prey at dawn in areas without the other
species. However, where their ranges overlap, the two-spot avenger beetle hunts at night and the
three-spot hunts in the morning. When you bring them into the laboratory and isolate the two
different species, you discover that the offspring of both species are found to be nocturnal. You
have discovered an example of _____.
A) mutualism
B) character displacement
C) Batesian mimicry
D) resource partitioning
Use the following diagram to answer the question(s) below.
In this experiment, Balanus was removed from the habitat shown on the left.
5) Which of the following statements is a valid conclusion of this experiment?
A) Balanus can survive only in the lower intertidal zone because it is unable to resist desiccation.
B) Balanus is inferior to Chthamalus in competing for space on rocks lower in the intertidal
zone.
C) The two species of barnacles do not compete with each other because they feed at different
times of day.
D) The removal of Balanus shows that the realized niche of Chthamalus is smaller than its
fundamental niche.
6) Connell conducted this experiment to learn more about _____.
A) character displacement in the color of barnacles
B) habitat preference in two different species of barnacles
C) how sea-level changes affect barnacle distribution
The symbols +, -, and o are to be used to show the results of interactions between individuals and
groups of individuals in the examples that follow. The symbol + denotes a positive interaction, -
denotes a negative interaction, and o denotes where individuals are not affected by interacting.
The first symbol refers to the first organism mentioned.
7) What interactions exist between a lion pride and a hyena pack?
A) +/+
B) +/-
C) o/o
D) -/-
8) What interactions exist between a tick on a dog and the dog?
A) +/o
B) +/-
C) o/o
D) -/-
9) Which of the following statements is consistent with the principle of competitive exclusion?
A) The random distribution of one competing species will have a positive impact on the
population growth of the other competing species.
B) Two species with the same fundamental niche will exclude other competing species.
C) Even a slight reproductive advantage will eventually lead to the elimination of the less well
adapted of two competing species.
D) Natural selection tends to increase competition between related species.
10) If two species are close competitors, and one species is experimentally removed from the
community, the remaining species would be expected to _____.
A) change its fundamental niche
B) decline in abundance
C) become the target of specialized parasites
D) expand its realized niche
11) Which of the following is an example of a commensalism?
A) fungi residing in plant roots, such as endomycorrhizae
B) bacteria fixing nitrogen in plants
C) rancher ants that protect aphids in exchange for sugar-rich honeydew
D) cattle egrets eating insects stirred up by grazing bison
12) Treehoppers (a type of insect) produce honeydew, which ants use for food. Treehoppers have
a major predator, the jumping spider. Researchers hypothesized that the ants would protect the
treehoppers from the spiders. In an experiment, researchers followed study plots with ants
removed from the system and compared them to a control plot. In the figure above, what can you
conclude?
A) Ants do somehow protect the treehoppers from spiders.
B) Ants eat the honeydew produced by treehoppers
C) Ants reduce the numbers of treehoppers.
D) No specific conclusions can be drawn from this figure.
13) During a one-year study, researchers found no difference in treehopper populations in any of
their control and experimental groups. What could they measure during the second year to gain
information about why this might have occurred?
A) Measure the number of ant females.
B) Measure the relative sizes of the treehoppers.
C) Measure the relative abundance of jumping spiders.
D) Measure the relative sizes of different ant species.
14) Resource partitioning would be most likely to occur between _____.
A) sympatric populations of species with similar ecological niches
B) sympatric populations of a flowering plant and its specialized insect pollinator
C) allopatric populations of the same animal species
D) allopatric populations of species with similar ecological niches
15) Which of the following is an example of cryptic coloration?
A) bands on a coral snake
B) brown or gray color of tree bark
C) markings of a viceroy butterfly's wings
D) a "walking stick" insect that resembles a twig
16) Which of the following is an example of Müllerian mimicry?
A) two species of unpalatable butterfly that have the same color pattern
B) a day-flying hawkmoth that looks like a wasp
C) a chameleon that changes its color to look like a dead leaf
D) two species of rattlesnakes that both rattle their tails
17) Which of the following is an example of Batesian mimicry?
A) a butterfly that resembles a leaf
B) a nonvenomous snake that looks like a venomous snake
C) a fawn with fur coloring that camouflages it in the forest environment
D) a snapping turtle that uses its tongue to mimic a worm, thus attracting fish
18) Which of the following is an example of aposematic coloration?
A) the brightly colored patterns of poison dart frogs
B) eye color in humans
C) green color of a plant
D) a katydid whose wings look like a dead leaf
19) Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain nutrients
and water from the vascular tissues of the trees. The trees derive no known benefits from the
dwarf mistletoes. Which of the following best describes the interactions between dwarf
mistletoes and trees?
A) mutualism
B) parasitism
C) competition
D) facilitation
20) In some circumstances, grasses benefit from being grazed. Which of the following terms
would best describe such a plant-herbivore interaction?
A) mutualism
B) commensalism
C) parasitism
D) predation
21) Which of the following would be most significant in understanding the structure of an
ecological community?
I) determining how many species are present overall
II) determining which particular species are present
III) determining the kinds of interactions that occur among organisms of different species
IV) determining the relative abundance of species
A) only I and III
B) only II and IV
C) only I, II, and III
D) I, II, III, and IV
22) Which of the following studies would a community ecologist undertake to learn about
competitive interactions?
I) selectivity of nest sites among cavity-nesting songbirds
II) the grass species preferred by grazing pronghorn antelope and bison
III) stomach analysis of brown trout and brook trout in streams where they coexist
A) only I and II
B) only I and III
C) only II and III
D) I, II, and III
23) How might an ecologist test whether a species is occupying all of its fundamental niche or
only a portion of it?
A) Study the temperature range and humidity requirements of the species.
B) Observe if the niche size changes after the introduction of a similar non-native species.
C) Measure the change in reproductive success when the species is subjected to environmental
stress.
D) Observe if the species expands its range after the removal of a competitor.
The symbols +, -, and o are to be used to show the results of interactions between individuals and
groups of individuals in the examples that follow. The symbol + denotes a positive interaction, -
denotes a negative interaction, and o denotes where individuals are not affected by interacting.
The first symbol refers to the first organism mentioned.
24) What interactions exist between cellulose-digesting organisms in the gut of a termite and the
termite?
A) +/+
B) +/o
C) +/-
D) o/o
25) What interactions exist between mycorrhizae and evergreen tree roots?
A) +/+
B) +/o
C) +/-
D) o/o
26) Bouchard and Brooks studied the effect of insect flight on dispersal and speciation in rain
forest insects. They sampled all of the insects in the study area and found that 60 insect species
are flightless and 19 are macropterous (able to fly). What can you conclude so far about this
study?
(P. Bouchard and D. R. Brooks. 2004. Effect of vagility potential on dispersal and speciation in
rainforest insects. Journal of Evolutionary Biology 17:994-1006.)
A) Flightless insects have a greater dispersal potential from this study area.
B) Flightless insects are more numerous in the study area.
C) Flightless insects have a higher richness in the study area.
D) Flightless insects are better suited for the tropics.
27) What does the graph in the figure above tell you about the definition of a keystone species?
A) A keystone species has little interaction with other species in an environment.
B) Removing a keystone species from the community drastically reduces diversity.
C) Adding a keystone species to the community will make it more diverse.
D) Removing a keystone species from the community will eventually allow for the invasion of a
new species.
28) In the figure above, which community has the highest species diversity?
A) Community 1
B) Community 2
C) Community 1 and community 3 have the highest species diversity.
D) Community 4
29) Approximately how many kilograms (kg) of carnivore (secondary consumer) biomass can be
supported by a field plot containing 1000 kg of plant material?
A) 1000
B) 100
C) 10
D) 1
30) In a tide pool, fifteen species of invertebrates were reduced to eight after one species was
removed. The species removed was likely a(n) _____.
A) pathogen
B) keystone species
C) herbivore
D) resource partitioner
31) 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?
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 are the biggest herbivore in this community.
D) Elephants help other populations survive by keeping out many of the large African predators.
32) According to bottom-up and top-down control models of community organization, which of
the following expressions would imply that an increase in the size of a carnivore (C) population
would negatively impact its prey (P) population, but not vice versa?
A) P ← C
B) P → C
C) C ↔ P
D) P ← C → P
33) Which of the following is a likely explanation for why invasive species take over
communities into which they have been introduced?
A) Invasive species are less efficient than native species in competing for the limited resources
of the environment.
B) Invasive species are not held in check by the predators and agents of disease that have always
been in place for native species.
C) Invasive species have a higher reproductive potential than native species.
D) Invasive species come from geographically isolated regions, so when they are introduced to
regions where there is more competition, they thrive.
34) Imagine five forest communities, each with one hundred individuals distributed among four
different tree species (W, X, Y, and Z). Which forest community would be most diverse?
A) 25W, 25X, 25Y, 25Z
B) 40W, 30X, 20Y, 10Z
C) 50W, 25X, 15Y, 10Z
Refer to the following art to answer the question below.
35) According to the Shannon Diversity Index, which of the five blocks above, with each
containing thirty-six squares, would show the greatest diversity?
A) 1
B) 2
C) 4
D) 5
Use the following diagram of a hypothetical food web to answer the question(s) below. The
arrows represent the transfer of energy between the various trophic levels.
36) Which letter represents an organism that could be a producer?
A) A
B) B
C) D
D) E
37) Which letter represents an organism that could only be a primary consumer?
A) A
B) B
C) C
D) D
38) Keystone predators can maintain species diversity in a community if they _____.
A) competitively exclude other predators
B) prey on the community's dominant species
C) allow immigration of other predators
D) prey only on the least abundant species in the community
39) Food chains are sometimes short because _____.
A) only a single species of herbivore feeds on each plant species
B) local extinction of a species causes extinction of the other species in its food chain
C) most of the energy in a trophic level is lost as it passes to the next higher level
D) predator species tend to be less diverse and less abundant than prey species
40) Which of the following could qualify as a top-down control on a grassland community?
A) limitation of plant biomass by rainfall amount
B) influence of temperature on competition among plants
C) influence of soil nutrients on the abundance of grasses versus wildflowers
D) effect of grazing intensity by bison on plant species diversity
41) Recall that Clements's view of biological communities is that of a highly predictable and
interrelated structure, while Gleason's view of biological communities is that individual species
operate independently. If we set up many identical sterilized ponds in the same area and allowed
them to be colonized, what should we predict if we wished to test Gleason's hypothesis?
A) Identical plankton communities will develop in all ponds.
B) Similar plankton communities will develop in all ponds.
C) Different plankton communities will develop in all ponds.
D) Limited plankton communities will develop in all ponds.
42) What is the main advantage of controlled burnings of forested areas? Controlled burnings
_____.
A) eliminate the possibility of forest fires
B) clear forested areas for farmland
C) prevent the overgrowth of the underbrush
D) allow new species to form
43) According to the nonequilibrium model of community diversity, _____.
A) community structure remains stable in the absence of interspecific competition
B) communities are assemblages of closely linked species that are irreparably changed by
disturbance
C) interspecific interactions induce changes in community composition over time
D) communities are constantly changing after being influenced by disturbances
44) Why do moderate levels of disturbance result in an increase in community diversity?
A) Habitats are opened up for less competitive species.
B) Competitively dominant species infrequently exclude less competitive species after a
moderate disturbance.
C) The resulting uniform habitat supports stability, which in turn supports diversity.
D) Less-competitive species evolve strategies to compete with dominant species.
45) Based on the intermediate disturbance hypothesis, a community's species diversity is
increased by _____.
A) frequent massive disturbance
B) stable conditions with no disturbance
C) moderate levels of disturbance
D) intensive disturbance by humans
46) In a particular case of secondary succession, three species of wild grass all invaded a field.
By the second season, a single species dominated the field. A possible factor in this secondary
succession was _____.
A) equilibrium
B) immigration
C) inhibition
D) parasitism
47) There are more species in tropical areas than in places more distant from the equator. This is
probably a result of _____.
A) fewer predators
B) more intense annual solar radiation
C) more frequent ecological disturbances
D) fewer agents of disease
48) Which of the following is a widely supported explanation for the tendency of tropical
communities to have greater species diversity than temperate or polar communities?
A) There are fewer parasites to negatively affect the health of tropical communities.
B) Tropical communities are low in altitude, whereas temperate and polar communities are high
in altitude.
C) Tropical communities are generally older than temperate and polar communities.
D) More competitive dominant species have evolved in temperate and polar communities.
49) Which of the following is a correct statement about the MacArthur/Wilson Island
Biogeography Model?
A) As the number of species on an island increases, the emigration rate decreases.
B) Competitive exclusion is less likely on an island that has large numbers of species.
C) Small islands receive few new immigrant species.
D) Islands closer to the mainland have higher extinction rates.
50) Which island would likely have the greatest species diversity?
A) A
B) C
C) D
D) E
51) Which island would likely exhibit the most impoverished species diversity?
A) A
B) B
C) C
D) E
52) Which island would likely have the lowest extinction rate?
A) A
B) C
C) D
D) E
53) According to the equilibrium model of island biogeography, species richness would be
greatest on an island that is _____.
A) large and close to a mainland
B) large and remote
C) small and remote
D) small and close to a mainland
54) The most plausible hypothesis to explain why species richness is higher in tropical than in
temperate regions is that _____.
A) tropical communities are younger
B) tropical regions generally have more available water and higher levels of solar radiation
C) higher temperatures cause more rapid speciation
D) tropical regions have very high rates of immigration and very low rates of extinction
55) Zoonotic disease _____.
A) is caused by suborganismal pathogens such as viruses, viroids, and prions only
B) is caused by pathogens that are transferred from other animals to humans by direct contact or
by means of a vector
C) can only be spread from animals to humans through direct contact
D) can only be transferred from animals to humans by means of an intermediate host
56) Why is a pathogen generally more virulent in a new habitat?
A) Intermediate host species are more motile and transport pathogens to new areas.
B) Pathogens evolve more efficient forms of reproduction in new environments.
C) Hosts in new environments have not had a chance to become resistant to the pathogen through
natural selection.
D) New environments are almost always smaller in area so that transmission of pathogens is
easily accomplished between hosts.
57) Which of the following best describes the consequences of white-band disease in Caribbean
coral reefs?
A) Staghorn coral is decimated by the pathogen, and Elkhorn coral takes its place.
B) Key habitat for lobsters, snappers, and other reef fishes improves.
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.
58) Which of the following studies would shed light on the mechanism of spread of H5N1 virus
from 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.
59) In terms of community ecology, why are pathogens often more virulent now than in the past?
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.
60) The oak tree fungal pathogen, Phytophthora ramorum, has migrated eight hundred
kilometers in fifteen years. West Nile virus spread from New York State to forty-six other states
in five years. The difference in the rate of spread is probably related to _____.
A) the lethality of each pathogen
B) the mobility of their hosts
C) the fact that viruses are very small
D) innate resistance
61) Scientists interested in how populations interact within communities are attempting to
determine the species diversity of an island under study. What kind of data would be most
helpful to the scientists in determining diversity?
A) The number of different species on the island and the size of the population of each species.
B) The number of species on the island that are consumers, producers, and decomposers.
C) The relative biomass of each species on the island separated by trophic level.
D) The number of trophic levels on the island and the niche of each species.
62) Red-cheeked salamanders are partially protected from predators because of cardiac
glycosides they produce from glands on their back. When ingested, cardiac glycosides disrupt
normal heart rhythms. A different salamander species, the imitator salamander, also has red
cheek patches, but does not produce cardiac glycosides. It does gain protection from predators
that have learned to avoid red cheeked salamanders. How does this relationship affect the
population dynamics of both species?
A) Both species are negatively affected.
B) Both species are positively affected.
C) The red cheeked salamander is positively affected, the imitator is negatively affected.
D) The red cheeked salamander is negatively affected, the imitator is positively affected.
