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Life: The Science of Biology, Ninth Edition
Sadava • Hillis • Heller • Berenbaum
Chapter 56: Species Interactions and Coevolution
TEST FILE QUESTIONS
(By Norman Johnson)
Multiple Choice
1. Leaf-cutter ants that tend fungal gardens protect themselves from mold by means of
a. their feces.
b. the fungi.
c. bacteria.
d. a smaller ant species.
e. None of the above
Answer: c
Textbook Reference: 56.0 Anty biotics
Page: 1185
Bloom’s Category: 1. Remembering
2. Which of the following statements about leaf-cutter ants is true?
a. They fertilize their fungus gardens with their own feces.
b. Most colonies collect more than a kilogram of plant material per day.
c. The ants feed directly from the leaves they collect.
d. Both a and b
e. Both b and c
Answer: d
Textbook Reference: 56.0 Anty biotics
Page: 1185
Bloom’s Category: 1. Remembering
3. The relationship between a zebra and the lion that eats it is an example of what kind of
relationship?
a. Competition
b. Mutualism
c. Antagonistic
d. Commensalism
e. Amensalism
Answer: c
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 2. Understanding
4. Which of the following does not involve antagonistic relationships?
a. Parasitism
b. Predation
c. Herbivory
d. Competition
e. All of the above involve antagonistic relationships.
Answer: d
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 1. Remembering
5. Which of the following is an example of a mutualistic interaction?
a. Barnacles obtain safe haven by riding on a whale, while the whale is unaffected.
b. A bacterium fixes nitrogen, thereby providing nutrient for a plant, while the plant
provides protection for the bacterium.
c. A virus infects a bird, thus reducing the bird’s fecundity.
d. Both a and b
e. None of the above
Answer: b
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 2. Understanding
6. Two species of beetles are both herbivores on the same host plant, and the presence of
either species reduces the population growth of the other. The relationship between the
beetles is best described as
a. antagonistic.
b. predation.
c. herbivory.
d. competition.
e. amensalism.
Answer: d
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 2. Understanding
7. Which of the following relationships has negative consequences for both species
involved?
a. Predation
b. Competition
c. Amensalism
d. Parasitism
e. Aposematism
Answer: b
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 1. Remembering
8. Suppose the fecal matter from dogs helps fertilize a particular species of plant, thus
increasing the plant’s ability to grow in a particular area. The relationship between the
dogs and the plants would be described as
a. mutualism.
b. amensalism.
c. herbivory.
d. antagonistic.
e. commensalism.
Answer: e
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1187
Bloom’s Category: 2. Understanding
9. While hunting, a bear smashes into and destroys a bush, and then continues pursuing
its prey. The relationship between the bear and the bush would be described as
a. herbivory.
b. antagonistic.
c. amensalism.
d. commensalism.
e. predation.
Answer: c
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1187
Bloom’s Category: 2. Understanding
10. Another term for coevolution is
a. amensalism.
b. commensalism.
c. aposematism.
d. reciprocal adaptation.
e. character displacement.
Answer: d
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1188
Bloom’s Category: 1. Remembering
11. Which of the following relationships is least likely to result in coevolution?
a. Mutualism
b. Host–parasite
c. Predator–prey
d. Competition
e. Amensalism
Answer: e
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1188
Bloom’s Category: 1. Remembering
12. Coevolutionary “arms races” are usually the result of
a. amensalism.
b. responses to abiotic conditions.
c. reciprocal adaptations.
d. commensalism.
e. None of the above
Answer: c
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1188
Bloom’s Category: 1. Remembering
13. Which of the following statements about a predator–prey relationship is true?
a. It is an antagonistic relationship.
b. The predators tend to be more specialized than other types of consumers.
c. The relationship has negative consequences for both species involved.
d. Both a and b
e. Both b and c
Answer: a
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1189
Bloom’s Category: 1. Remembering
14. Suppose a survey of predator–prey relationships shows that the fastest predators are
usually found in regions where the fastest prey also are found. The most likely
explanation for such a finding is
a. character displacement.
b. reciprocal adaptations.
c. aposematism.
d. exploitative competition.
e. the Batesian principle.
Answer: b
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1189
Bloom’s Category: 2. Understanding
15. Bombardier beetles are best known for their
a. ability to mimic other, more toxic beetles.
b. crypsis.
c. ability to escape from predators by means of their extraordinarily quick reflexes.
d. chemical defenses.
e. extraordinary polyphagy.
Answer: d
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1189
Bloom’s Category: 1. Remembering
16. Which of the following statements about chemical defenses of prey is true?
a. Prey that use chemical defenses tend to be slow-moving.
b. Some predators can evolve countermeasures against the chemical defenses of prey.
c. Many prey species that defend themselves with toxic chemicals advertise their toxicity.
d. Both a and b
e. Both b and c
Answer: e
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1189
Bloom’s Category: 1. Remembering
17. The sharp contrast of black and white on a skunk warns other animals to stay away,
lest they face a noxious spray. This defense is an example of
a. Batesian mimicry.
b. amensalism.
c. character displacement.
d. crypsis.
e. aposematism.
Answer: e
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1189
Bloom’s Category: 2. Understanding
18. What is the major difference between Batesian and Müllerian mimicry?
a. Only Batesian mimicry involves reciprocal adaptations.
b. Only Müllerian mimicry involves reciprocal adaptations.
c. All of the species that exhibit Müllerian mimicry are toxic; in Batesian mimicry, one or
more species are toxic and one or more species are nontoxic mimics.
d. All of the species that exhibit Batesian mimicry are toxic; in Müllerian mimicry, one or
more species are toxic and one or more species are nontoxic mimics.
e. There is no difference between Müllerian and Batesian mimicry.
Answer: c
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190
Bloom’s Category: 1. Remembering
19. Many female swallowtail butterflies are not toxic, but they resemble butterflies that
are toxic. This phenomenon is known as
a. character displacement.
b. Müllerian mimicry.
c. Batesian mimicry.
d. Wallacean mimicry.
e. crypsis.
Answer: c
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190
Bloom’s Category: 2. Understanding
20. Three species of snails that are toxic to their bird predators have evolved similar
patterns of coloration that help notify the birds of their poisonous nature. This
phenomenon is best described as
a. Müllerian mimicry.
b. Batesian mimicry.
c. character displacement.
d. crypsis.
e. homotypy.
Answer: a
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190
Bloom’s Category: 2. Understanding
21. The opposite of crypsis is
a. homotypy.
b. commensalism.
c. antagonism.
d. aposematism.
e. character displacement.
Answer: d
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190
Bloom’s Category: 2. Understanding
22. Homotypy is a type of
a. aposematism.
b. Müllerian mimicry.
c. Batesian mimicry.
d. chemical defense.
e. crypsis.
Answer: e
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190
Bloom’s Category: 1. Remembering
23. Which of the following statements about herbivory is false?
a. At least hundreds of thousands of species engage in herbivory.
b. Herbivory is an antagonistic interaction.
c. Herbivory is found in marine as well as terrestrial systems.
d. Most herbivore species are insects.
e. All of the above are true; none is false.
Answer: e
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190–1191
Bloom’s Category: 1. Remembering
24. Drosophila sechellia, which is native to the Seychelles Islands, feeds only from the
Indian mulberry shrub. This species would therefore be called
a. polyphagous.
b. oligophagous.
c. aposematic.
d. amensalistic.
e. xeric.
Answer: b
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1191
Bloom’s Category: 2. Understanding
25. Caterpillars of the winter moth Operophtera brumata eat the leaves of a variety of
trees, including maples, oaks, cranberry, blueberry, and apple. The feeding habits of this
moth would therefore be called
a. aposematic.
b. oligophagous.
c. polyphagous.
d. homotypic.
e. pathogenic.
Answer: c
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1191
Bloom’s Category: 2. Understanding
26. Which of the following statements about the relationship between plants and animals
is correct?
a. Because vertebrates are more likely than insects to be herbivores, plants have not
needed to evolve responses against insect herbivory.
b. Because herbivorous insects usually do not kill the plants they feed on, their role as a
selective agent is questionable.
c. Because most plants live a long time, they are less likely to be able to evolve defenses
against the herbivores.
d. The fact that most insects are able to eat a wide variety of plants suggests that plant
defenses are ineffective.
e. The fact that insects do not exhibit character displacement argues against their ability
to coevolve with any other life form.
Answer: b
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1191
Bloom’s Category: 2. Understanding
27. Which of the following statements about herbivory is true?
a. Most insects are specialized herbivores, usually feeding from one or a few host plants.
b. Most vertebrates are specialized herbivores, usually feeding from one or a few host
plants.
c. In most natural ecosystems, insects usually remove less than 20 percent of plant
biomass.
d. Both a and b
e. Both a and c
Answer: e
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1191
Bloom’s Category: 1. Remembering
28. Most plants defend themselves against herbivory mainly by means of
a. aposematism.
b. crypsis.
c. thorns and spines.
d. silica.
e. chemical defenses.
Answer: e
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1191
Bloom’s Category: 1. Remembering
29. Which of the following is most responsible for the biochemical diversity of plants?
a. Adaptations to different soils
b. Adaptations to different temperature regimes
c. Adaptations to different levels of moisture
d. Coevolution with herbivores
e. Coevolution with commensals
Answer: d
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1192
Bloom’s Category: 1. Remembering
30. Which of the following is most likely to evolve specialized detoxification systems?
a. A mammalian herbivore that eats a variety of plant species
b. An avian predator
c. An insect whose larvae feed from the leaves from a single host plant
d. A bumblebee that obtains nectar while pollinating flowers
e. A tick that lives as an ectoparasite
Answer: c
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1192
Bloom’s Category: 2. Understanding
31. Monarch butterflies are toxic to many of their predators because they
a. have a mutualistic relationship with a fungus that produces a toxin in exchange for
nutrition.
b. have a mutualistic relationship with a bacterium that produces a toxin in exchange for
nutrition.
c. eat milkweed and are able to sequester the toxins from that plant.
d. have evolved an enzyme that produces a toxin.
e. None of the above
Answer: c
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1192
Bloom’s Category: 2. Understanding
32. The H1N1 influenza virus responsible for the 2009 pandemic is considered a(n)
a. microparasite.
b. macroparasite.
c. ectoparasite.
d. oligoparasite.
e. mutualist.
Answer: a
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1192
Bloom’s Category: 1. Remembering
33. Which of the following are most likely to be pathogens?
a. Macroparasites
b. Ectoparasites
c. Microparasites
d. Cryptoparasites
e. None of the above
Answer: c
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1192–1193
Bloom’s Category: 1. Remembering
34. Which of the following statements about pathogens and their hosts is true?
a. Pathogens are always selected evolutionarily to kill their host as quickly as possible.
b. Increased host resistance can lead to stable coexistence between pathogen and host.
c. Hosts are classified as susceptible, immune, or recovered.
d. Both a and b
e. Both b and c
Answer: b
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1193
Bloom’s Category: 1. Remembering
35. Which of the following would be most likely to evolve adaptations that would enable
them to grasp onto and maintain a tight grip on their hosts?
a. Amensals
b. Ectoparasites
c. Microparasites
d. Herbivores
e. Guild parasites
Answer: b
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1193
Bloom’s Category: 1. Remembering
36. Which of the following statements about mutualistic interactions is true?
a. They are almost always symmetrical.
b. They can evolve into parasitism.
c. They usually evolve when resources are common.
d. All of the above
e. None of the above
Answer: b
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1194
Bloom’s Category: 1. Remembering
37. Under which of the following conditions would a mutualistic relationship most likely
lead to reciprocal adaptations?
a. When the mutualism is asymmetrical
b. When both partners are animals
c. When one partner is an animal and the other is a plant
d. When both partners are plants
e. When increased benefits are gained by greater dependence on the partner
Answer: e
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1194
Bloom’s Category: 1. Remembering
38. The most likely pollinator of a plant species with orange, sweet-smelling flowers that
provide both nectar and pollen would be
a. moths.
b. butterflies.
c. hummingbirds.
d. bees.
e. flesh flies.
Answer: d
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1194
Bloom’s Category: 2. Understanding
39. The most likely pollinator of the scarlet monkeyflower Mimulus cardinalis, which has
bright red, tubular flowers and produces nectar, would be
a. moths.
b. butterflies.
c. hummingbirds.
d. bees.
e. flesh flies.
Answer: c
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1194
Bloom’s Category: 2. Understanding
40. Which of the following statements about plant-pollination systems is true?
a. Pollinators usually eat all of a plant’s pollen.
b. Successful pollination usually requires that the pollinator visit at least two members of
the plant species.
c. Pollinators usually have evolved specialized anatomical features to carry pollen.
d. Both a and b
e. Both b and c
Answer: e
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1194
Bloom’s Category: 2. Understanding
41. Compared with pollen, nectar
a. provides a greater reward.
b. is more susceptible to theft.
c. evolved earlier.
d. Both a and b
e. Both b and c
Answer: d
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1194
Bloom’s Category: 1. Remembering
42. The evolution of similar traits on the part of species that experience similar selective
pressures is a phenomenon called
a. Batesian mimicry.
b. character displacement.
c. diffuse coevolution.
d. aposematism.
e. mutualism.
Answer: c
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1195
Bloom’s Category: 1. Remembering
43. Which of the following statements about yucca plants is true?
a. They are pollinated by several species of bees as well as by yucca moths.
b. The stigma of the yucca flower is located deep within the pistil.
c. They are pollinated by moths that have evolved specialized mouthparts with long
tentacles.
d. Both a and b
e. Both b and c
Answer: e
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1195
Bloom’s Category: 1. Remembering
44. Which of the following statements about plant–frugivore mutualisms is true?
a. These mutualisms are usually symmetrical.
b. Most frugivores are specialists.
c. Plants time the ripening of their fruits to coincide with the maturation of their seeds.
d. Both a and b
e. None of the above
Answer: c
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1195
Bloom’s Category: 1. Remembering
45. The relationship between mistletoes and mistletoe birds is one in which food is traded
for
a. whole plant transport.
b. defense.
c. pollen transport.
d. seed transport.
e. None of the above
Answer: d
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1196
Bloom’s Category: 1. Remembering
46. Southern pine bark beetles and leaf-cutter ants are similar in that both
a. display aposematic color patterns.
b. depend on mutualisms with fungi.
c. prey on other insects.
d. exhibit character displacement.
e. None of the above
Answer: b
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1196
Bloom’s Category: 1. Remembering
47. The primary benefit that acacia trees receive from their association with ants is
a. seed transport.
b. pollen transport.
c. nitrogen products.
d. potassium products.
e. protection.
Answer: e
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1197
Bloom’s Category: 1. Remembering
48. Two species of yeast are capable of persisting indefinitely on agar in the lab, but
when they are grown together under similar conditions, only a single species remains
after a few days. This is an illustration of
a. character displacement.
b. interference competition.
c. intraspecific competition.
d. competitive exclusion.
e. homotypy.
Answer: d
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1198
Bloom’s Category: 2. Understanding
49. Two similar species of lemurs exist in Madagascar. One species eats leaves from the
understory of trees, and the other eats leaves from the top of those trees. This
phenomenon would be described as
a. competitive exclusion.
b. interference competition.
c. exploitative competition.
d. resource partitioning.
e. character displacement.
Answer: d
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1198
Bloom’s Category: 2. Understanding
50. Two species of woody shrubs are in close proximity and in competition for limited
resources. One species produces chemicals through its roots that limit the growth of the
other. The production of these chemicals is a form of
a. intraspecific competition.
b. interference competition.
c. competitive exclusion.
d. resource partitioning.
e. exploitative competition.
Answer: b
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1198
Bloom’s Category: 2. Understanding
51. Which of the following statements about competition is false?
a. Some microorganisms engage in interference competition.
b. Interspecific competition can lead to species extinction.
c. Competition plays an important role in determining the composition of communities.
d. Competition can take place only between members of different species.
e. All of the above are true; none is false.
Answer: d
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1198
Bloom’s Category: 2. Understanding
52. The logical chain between interspecific competition, guild formation, and resource
partitioning is that _______ caused _______, which led to _______.
a. interspecific competition; guild formation; resource partitioning
b. interspecific competition; resource partitioning; guild formation
c. guild formation; interspecific competition; resource partitioning
d. guild formation; resource partitioning; interspecific competition
e. resource partitioning; interspecific competition; guild formation
Answer: b
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1198
Bloom’s Category: 2. Understanding
53. Robert Denno’s studies on sap-sucking planthoppers showed that these species
engage in _______ as a response to competition.
a. character displacement
b. antagonistic interactions
c. niche realization
d. reciprocal adaptations
e. resource partitioning
Answer: e
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1199
Bloom’s Category: 1. Remembering
54. After the introduction of the American mink into Belarus, the native European mink
became larger, and the American mink gradually decreased in size. Which of the
following is the most likely explanation for this observation?
a. Antagonistic interactions
b. Interference competition
c. Character displacement
d. Guild formation
e. Batesian mimicry
Answer: c
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1199
Bloom’s Category: 2. Understanding
55. Which of the following is an example of character displacement?
a. Early in its growing season, scarlet gilia produces red flowers that attract
hummingbirds; later in the season, the plant produces white flowers that attract
hawkmoths.
b. Large polyphagous herbivores usually eat a wide variety of plants in order to minimize
their exposure to the toxins of any one plant.
c. A species of butterfly that is edible by bird predators evolves the color patterns of
another butterfly species that is toxic to the predators.
d. Finches in the Galápagos Islands are larger on islands where bees are present because
the bees compete with the finches for cactus nectar.
e. None of the above
Answer: d
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1199
Bloom’s Category: 2. Understanding
56. Which of the following statements about competition is true?
a. Consumers can influence the outcome of their prey species’ competitive interactions.
b. Competition requires the competitors to be physically present in the same region at the
same time.
c. Exploitation competition cannot lead to coexistence.
d. Both a and b
e. None of the above
Answer: a
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1199
Bloom’s Category: 2. Understanding
57. What would be the best explanation for the observation that the range of a species of
lacewings has expanded following the removal of a competitor?
a. The absence of the competitor caused the species to undergo character displacement.
b. The presence of the competitor had caused the species to undergo character
displacement.
c. In the presence of the competitor, the realized niche of the species had been larger than
its fundamental niche.
d. In the presence of the competitor, the realized niche of the species had been smaller
than its fundamental niche.
e. Consumers may influence the outcome of competition.
Answer: d
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1200
Bloom’s Category: 2. Understanding
58. According to the results of Connell’s experiments, the distribution of stellate
barnacles is restricted by
a. desiccation.
b. cold temperatures.
c. predation.
d. competition.
e. parasitism.
Answer: d
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1200
Bloom’s Category: 1. Remembering
59. According to the results of Connell’s experiments, the distribution of rock barnacles
is restricted by
a. desiccation.
b. cold temperatures.
c. predation.
d. competition.
e. parasitism.
Answer: a
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1200
Bloom’s Category: 1. Remembering
60. Which of the following interactions would most likely make a species’ realized niche
larger than its fundamental niche?
a. Competition
b. Predation
c. Mutualism
d. Both a and b
e. Both b and c
Answer: c
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1200
Bloom’s Category: 4. Analyzing
61. The intertidal zonation seen in the barnacles in Connell’s studies is due to
a. competitive interactions and predation.
b. competitive interactions and differential susceptibility to abiotic conditions.
c. predation and differential susceptibility to abiotic conditions.
d. susceptibility to abiotic conditions and parasitism.
e. parasitism and predation.
Answer: b
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1200
Bloom’s Category: 2. Understanding
Fill in the Blank
1. Parasitism and predation are both forms of _______ interactions.
Answer: antagonistic
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 1. Remembering
2. A rabbit unwittingly carries a mite across the river at no cost to itself. This is an
example of _______.
Answer: commensalism
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1187
Bloom’s Category: 2. Understanding
3. The type of interaction in which one partner is harmed but there is no effect on the
other is called _______.
Answer: amensalism
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1187
Bloom’s Category: 1. Remembering
4. Many exquisite adaptations are actually the result of reciprocal adaptations, or
_______, between partners of an interaction.
Answer: coevolution
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1188
Bloom’s Category: 1. Remembering
5. Many snakes, particularly those that are venomous, exhibit patterns of vibrant
coloration that serve to advertise their toxicity. These color patterns are an example of
_______.
Answer: aposematism (or aposematic coloration)
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1189
Bloom’s Category: 2. Understanding
6. In _______ mimicry, one species that is not hazardous evolves coloration or behaviors
that are similar to those of a hazardous species. The nonhazardous species is called the
_______, whereas the hazardous species is called the _______.
Answer: Batesian; mimic; model
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190
Bloom’s Category: 1. Remembering
7. A snail that evolves measures to look like an inedible object demonstrates the form of
mimicry known as _______.
Answer: homotypy
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190
Bloom’s Category: 2. Understanding
8. Taxonomically, most of the world’s herbivores are _______.
Answer: insects
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1191
Bloom’s Category: 1. Remembering
9. Larvae of moths called bagworms can eat a tremendous variety of plants; some species
can consume leaves from more than 40 different host plant families. Bagworms are thus
_______ herbivores.
Answer: polyphagous
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1191
Bloom’s Category: 2. Understanding
10. Most of the great diversity of plant biochemistry is due to _______ adaptations
between plants and insect herbivores.
Answer: reciprocal
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1192
Bloom’s Category: 1. Remembering
11. Hosts of pathogens can be classified as _______, infected, or recovered.
Answer: susceptible
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1193
Bloom’s Category: 1. Remembering
12. In addition to being macroparasites, ticks are usually _______ because they often live
outside their host.
Answer: ectoparasites
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1193
Bloom’s Category: 2. Understanding
13. In many pollination systems, nectar serves as a(n) _______, luring the pollinator to
visit the flower.
Answer: attractant (or reward)
Textbook Reference: 56.3 How Do Mutalistic Inter-actions Evolve?
Page: 1194
Bloom’s Category: 1. Remembering
14. Bats usually pollinate flowers that have a _______ odor.
Answer: musty
Textbook Reference: 56.3 How Do Mutalistic Interactions Evolve?
Page: 1194
Bloom’s Category: 1. Remembering
15. In the exchange between plants and frugivores, plants exchange food for _______.
Answer: seed transport
Textbook Reference: 56.3 How Do Mutalistic Interactions Evolve?
Page: 1196
Bloom’s Category: 1. Remembering
16. Two species of aphids compete for the same resource, and neither interferes with the
other. This is an example of both _______ competition and _______ competition.
Answer: interspecific; exploitation
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1198
Bloom’s Category: 2. Understanding
17. The likelihood that a species of spadefoot toad will develop into a carnivore morph
(as opposed to an omnivore morph) depends on whether it is in the vicinity of a
competitor. This dependence is an example of _______.
Answer: character displacement
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1199
Bloom’s Category: 2. Understanding
18. If the removal of a predator results in expansion of a spider’s range, it is likely that
the spider’s _______ niche is larger than its _______ niche in the presence of predators.
Answer: fundamental; realized
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1200
Bloom’s Category: 2. Understanding
Diagram
1.–2. A hypothetical group of researchers is conducting a study to investigate whether
character displacement is occurring in grasshopper species. This species has a range in
which it shares some area with a competitor, while in other areas the competitor is
missing. The diagram below shows the results for the three traits that were measured:
tibia length, femur length, and mouthpart size. The measurements for the focal species in
the absence of the competitor and the focal species in the presence of the competitor are
designated A and A´, respectively. Panel B shows the measurements of the competitor.
1. Which traits show evidence of character displacement in species A?
a. Tibia length
b. Femur length
c. Mouthpart size
d. Both a and b
e. Both a and c
Answer: a
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1199
Bloom’s Category: 4. Analyzing
2. How would one test whether the differences that may have arisen due to character
displacement are the result of genetic changes or just an environmental response?
Answer: The simplest way to determine whether the response is genetic would be to rear
individuals of species A under the same conditions where the competitor is present and
also where it is absent. If the differences persist, then they are genetic.
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1199–1200
Bloom’s Category: 6. Creating
STUDY GUIDE QUESTIONS
(By Lindsay Goodloe)
Knowledge and Synthesis
1. Which of the following does not describe an antagonistic interaction between two
living organisms?
a. Sheep grazing on grass in a pasture
b. A robin catching and eating a worm
c. A flea biting a dog to obtain a blood meal
d. Lions skirmishing with hyenas to prevent them from feeding from a zebra carcass
e. All of the above describe antagonistic interactions.
Answer: d
Feedback: Antagonistic interactions are those in which one species benefits and the other
species is harmed. They include herbivory, predation, and parasitism. The competition
between the lions and hyenas for food is harmful to both species and hence is not
classified as an antagonistic interaction.
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186–1187
2. Certain birds follow swarms of foraging army ants and prey upon the insects that the
ants flush out. The relationship between these birds and the ants is an example of
a. competition.
b. commensalism.
c. mutualism.
d. amensalism.
e. Both a and b
Answer: e
Feedback: Both ants and birds are competing for the same food supply; the birds also
benefit from the ants’ activity in flushing out the insects, but the ants might not be
affected.
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186–1187
3. Which of the following types of interaction would be least likely to lead to coevolution
of the interacting species?
a. Predator–prey
b. Commensal
c. Plant–herbivore
d. Parasite–host
e. Mutualistic
Answer: b
Feedback: The types of interactions most likely to lead to coevolution are those that have
a strong effect on all of the interacting species. In commensalism, one species benefits
from the interaction, but the other is unaffected by it.
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1188
4. If a species of plant that is trampled by an animal eventually evolves sharp spines that
prevent trampling, we can say that its association with the animal has changed from
_______ to _______.
a. amensalism; competition
b. amensalism; commensalism
c. commensalism; competition
d. commensalism; mutualism
e. commensalism; amensalism
Answer: a
Feedback: Initially the plant is harmed and the animal is unaffected (amensalism). After
the evolution of sharp spines, the two species are competitors for space.
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1187
5. As their name suggests, stick insects (“walking sticks”) strongly resemble sticks or
twigs. The most specific term for this method of avoiding detection by predators is
a. mimicry.
b. camouflage.
c. aposematism.
d. crypsis.
e. homotypy.
Answer: e
Feedback: Homotypy is the resemblance of a living organism to an object considered
inedible by its predators.
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190
6. Skunks, which are noted for their ability to spray would-be predators with a foulsmelling chemical, typically have a coat that is mostly black with contrasting white
stripes or spots. This color pattern is an example of
a. mimicry.
b. camouflage.
c. aposematism.
d. crypsis.
e. homotypy.
Answer: c
Feedback: Aposematism is warning coloration, frequently exhibited by toxic or
otherwise noxious species.
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1189–1190
7. The most common defense of plants against herbivores is
a. the production of secondary metabolites.
b. a waxy cuticle covering the surfaces of the leaves.
c. thorns or spines.
d. hairy leaves.
e. leaves containing silica, which wears down the teeth of herbivores.
Answer: a
Feedback: The production of toxic secondary metabolites is by far the most widespread
means by which plants defend themselves against herbivores.
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1191
8. Which of the following statements about microparasites is true?
a. Microparasite infection rates typically rise only when a sufficiently dense population of
susceptible host individuals is present.
b. Microparasites include viruses, bacteria, protists, and parasitic worms.
c. Microparasites are always pathogens.
d. Both a and c
e. All of the above
Answer: a
Feedback: Microparasites include viruses, bacteria, and protists—all of which are far
smaller than their hosts—but not multicellular parasites such as worms. Only those
microparasites that cause disease symptoms are considered pathogens.
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1192–1193
9. Which of the following statements about ectoparasites is false?
a. Many ectoparasites have evolved adaptations to keep them attached to their hosts.
b. Some ectoparasites have a relatively brief or casual association with their hosts.
c. Most ectoparasitic insects are highly specialized, sometimes feeding on only a single
host species.
d. Many ectoparasitic insects have lost their wings during the course of their evolution.
e. All of the above are true.
Answer: e
Feedback: The mosquito is an example of an ectoparasite that remains with the host only
long enough to feed. Lice and fleas are examples of ectoparasites that lack wings and that
are highly specific with regard to their hosts (lice more so than fleas). Figure 56.8
illustrates the winglessness of lice as well as their adaptations for remaining attached to
their host.
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1193
10. Match the following pollinators with the descriptions of the flowers that follow.
Bees
Flesh flies
Beetles
Butterflies
Moths
Hummingbirds
Bats
a. Pendant white flowers with a heavy odor
b. Irregularly shaped purplish flowers with the odor of carrion
c. Tubular red flowers with no perceptible odor
d. Irregularly shaped flowers with a sweet odor
e. Bowl-shaped white flowers with a faint odor
f. Cuplike white flowers with a musty odor
g. Flowers with a tubular platform and a faint odor
Answer:
a. Moths
b. Flesh flies
c. Hummingbirds
d. Bees
e. Beetles
f. Bats
g. Butterflies
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1194
11. The suites of floral characteristics listed in the question above have evolved to attract
various groups of pollinators through the process of
a. specific coevolution.
b. interspecific competition.
c. resource partitioning.
d. character displacement.
e. diffuse coevolution.
Answer: e
Feedback: Diffuse coevolution is the evolution of similar traits in species experiencing
similar selection pressures.
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1195
12. A bird eats the fruit of a plant species. The seeds are not digested and germinate in the
bird’s excrement at some distance from the parent plant. This is an example of
a. predation.
b. competition.
c. commensalism.
d. mutualism.
e. amensalism.
Answer: d
Feedback: Both species have benefited; the bird dispersed and provided fertilizer for the
plant’s seed, and the plant provided food for the bird.
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1196
13. In Eurasia, two closely related species of rock nuthatches (small birds that forage for
insects and spiders on bare, rocky ground) occur either separately, or in zones of
sympatry. Individuals of both species that exist in the former situation, with no
interspecies competition, have bills that are similar in length. But in their zone of
sympatry in Iran, one species has a longer bill than it has elsewhere and the other species
has a shorter bill. This is an example of _______ competition that has resulted in
_______.
a. exploitation; resource partitioning
b. exploitation; character displacement
c. interference; resource partitioning
d. interference; character displacement
e. None of the above
Answer: b
Feedback: Because bill length in these species is clearly related to the type of food
resources and foraging sites that the birds utilize, this case must be considered an
example of exploitation competition. It is also an example of character displacement,
because in both species bill length is dependent on the presence or absence of the
competing species. The Iranian populations of the two species have evolved so as to
minimize competition between them.
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1199
14. Which of the following is a possible outcome of competition involving two species?
a. Some individuals of both species experience reduced growth and reproductive rates.
b. One species excludes the other from a habitat it would occupy in the absence of
competition.
c. One species restricts the geographic range of the other species.
d. The species evolve to divide up the limiting resource and continue to coexist in the
same locality.
e. All of the above
Answer: e
Feedback: It is generally true that competition, whether intraspecific or interspecific,
causes reduced growth and reproductive rates of some individuals participating in the
competitive interaction. Interspecific competition in particular may lead to exclusion
from a habitat of one of the competing species (i.e., competitive exclusion), or to range
restriction, or to resource partitioning.
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1198–1199
15. Which of the following statements about the niche concept is false?
a. Compared to species with dissimilar niches, species with similar niches are likely to be
stronger competitors with one another.
b. Two species can occupy the same habitat but have different niches.
c. Guilds are groups of species that occupy the same niche.
d. The realized niche of a species is never larger than its fundamental niche, though they
may be identical in size.
e. All of the above are true.
Answer: c
Feedback: Guilds are defined as groups of species that exploit the same resource but in
slightly different ways. This definition implies that their niches are similar but not
identical. If their niches were identical, the principle of competitive exclusion would
prevent them from coexisting in the same locality.
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1198–1200
Application
1. Two of the main characters in the animated film Finding Nemo are anemonefish (also
known as clown fish), which live inside of sea anemones and are unaffected by their
stings. How is this relationship an example of the ways in which interactions between
species are not always easily classifiable?
Answer: The anemonefish clearly benefit from the interaction with their host by gaining
protection from their enemies. It is less clear that the sea anemones are unaffected (in
which case the relationship would be a commensalism). The anemones may gain
nutrients from the feces of the fish, or the fish may occasionally steal prey from the
anemones, or both. Thus the interaction could be mutualistic or competitive, or both
simultaneously.
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1187–1188
2. Some mimicry systems (e.g., those involving tropical butterflies) include several toxic
species and several palatable species, all of which are aposematic and resemble one
another closely. How would you classify these mimicry systems—Batesian, Müllerian, or
both? Why might natural selection have favored the evolution of such complex mimicry
systems?
Answer: This type of mimicry system is both Batesian and Müllerian. The palatable
species are Batesian mimics of the toxic species (the models), and the toxic species are
Müllerian mimics of one another (each species in a sense being both model and mimic).
Natural selection may have favored the convergence of these aposematic species on a
common color pattern because it is probably easier for predators to learn to avoid a single
pattern than multiple patterns.
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190
3. After the European rabbit was introduced into Australia in 1859, it quickly became a
devastating invasive species, causing the extinction or decline of many native animals
and plants, major damage to crops, and soil erosion. To control the exponential growth of
the population (which had grown to an estimated 600 million individuals from an original
24), biologists infected rabbits with the myxoma virus in 1950. It is estimated that in the
first years after introduction of the virus, as many as 99 percent of infected rabbits died.
Over a period of years, however, biologists observed an increase both in the average life
span of infected rabbits and in the percentage of rabbits surviving infection. How would
you explain these changes?
Answer: Natural selection favored the survival of those rabbits that by chance had
relatively high genetic resistance to the virus. Thus, one would predict that over time, the
rabbit population as a whole would evolve to become more resistant. One would also
predict selection on the mxyoma virus favoring slower or lesser lethality: a mutant strain
of the virus that allowed its host to survive for a longer period of time, or to not be killed
at all, would be more likely to be transmitted to new hosts than the original strain that
killed its host more quickly. Biologists studying this classic example of host–parasite
coevolution have documented these evolutionary changes in both the rabbit and virus
populations.
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1193
4. Review the description of Connell’s classic experiment on competition between
Semibalanus and Chthamalus barnacle populations (see Figure 56.16). Do you think that
the interaction between these species is an example of interference competition or
exploitation competition? Why?
Answer: Ecologists regard the interaction between the barnacle populations as an instance
of interference competition. Semibalanus individuals smother, crush, or dislodge
Chthamalus individuals but do not directly reduce the food resources available to them.
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1200
5. Describe an experiment that would enable you to assess the degree of interspecific
competition that exists between two rodent species living in the same habitat. How would
you interpret the results?
Answer: A removal experiment could be done in which one or the other species would be
removed in two similar areas. You then would look for changes in the abundance of the
remaining species. The species with the largest increase in population density would be
the one most affected by competition with the removed species.
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1200
TEXTBOOK SELF-QUIZ
1. Predation, herbivory, and parasitism are all examples of
a. antagonistic interactions.
b. mutualistic interactions.
c. commensal interactions.
d. amensal interactions.
e. competitive interactions.
Answer: a
2. In a coevolutionary arms race, after a plant evolves a novel chemical defense against
an herbivore,
a. the herbivore can be expected to go extinct.
b. the herbivore can be expected to disperse to new habitats.
c. the herbivore can be expected to evolve resistance to the plant’s defense.
d. the plant can be expected to colonize new habitats.
e. the plant can be expected to outcompete all other plants in the same environment.
Answer: c
3. Two organisms that use the same resources when those resources are in short supply
are said to be
a. predators.
b. competitors.
c. mutualists.
d. commensalists.
e. amensalists.
Answer: b
4. Damage caused to shrubs by branches falling from overhead trees is an example of
a. interference competition.
b. partial predation.
c. amensalism.
d. commensalism.
e. diffuse coevolution.
Answer: c
5. A hummingbird sips nectar from the flowers of a plant species and, in the process,
pollinates those flowers. This interaction is best classified as
a. parasitism, because the hummingbird consumes the flower’s nectar.
b. predation, because the hummingbird eats the plant’s seeds.
c. commensalism, because the hummingbird benefits from consuming nectar and the
plant is unaffected.
d. mutualistic, because the plant provides nectar for the hummingbird and the
hummingbird transports pollen for the plant.
e. Not enough information is provided to classify this interaction.
Answer: d
6. Bright coloration that warns predators of prey toxicity is called
a. aposematism.
b. crypsis.
c. homotypy.
d. amensalism.
e. character displacement.
Answer: a
7. The type of mimicry in which a palatable species resembles a toxic species is called
a. Müllerian.
b. Batesian.
c. diffuse.
d. commensal.
e. homotypy.
Answer: b
8. Interference competition has been demonstrated to occur between
a. species of barnacles in the rocky intertidal zone.
b. species of ants in the deserts of North America.
c. species of soil bacteria that produce antibiotics.
d. All of the above
e. None of the above
Answer: d
9. One factor that can constrain the realized niche occupied by an organism is
a. immigration.
b. aposematism.
c. mimicry.
d. parasitism.
e. competition.
Answer: e
10. The principle of competitive exclusion states that
a. no two species can coexist unless they are sharing the same resource.
b. no two species can long coexist if they are sharing the same limiting resource.
c. if two species are sharing the same resource, one will always go extinct.
d. competition between two species always results in character displacement.
e. None of the above
Answer: b
BIOPORTAL DIAGNOSTIC QUIZ (Personalized Study Plan Quiz)
(By Nancy Murray)
1. If two organisms use the same resources and those resources are insufficient to supply
their combined needs, the organisms’ interactions constitute
a. amensalism.
b. mutualism.
c. commensalism.
d. predator–prey.
e. competition.
Answer: e
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 2. Understanding
2. The interaction between some plants and the ants that protect them is best described as
a. mutualism.
b. amensalism.
c. commensalism.
d. competition.
e. predation.
Answer: a
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 2. Understanding
3. Predation is the type of interaction in which
a. one participant benefits and the other is unaffected.
b. two organisms use the same limited resources.
c. one participant is harmed while the other benefits.
d. one participant is harmed but the other is unaffected.
e. both participants benefit.
Answer: c
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 2. Understanding
4. Mutualism is the type of interaction in which
a. one participant benefits and the other is unaffected.
b. two organisms use the same limited resources.
c. one participant is harmed while the other benefits.
d. one participant is harmed but the other is unaffected.
e. both participants benefit.
Answer: e
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 2. Understanding
5. _______ interactions benefit a consumer while harming the species that is consumed.
a. Mutualistic
b. Antagonistic
c. Agonistic
d. Both a and c
e. None of the above
Answer: b
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186
Bloom’s Category: 2. Understanding
6. Which of the following types of interactions is beneficial to one partner and
detrimental to the other partner?
a. Parasitism.
b. Mutualism.
c. Commensalism.
d. Amensalism.
e. Competition.
Answer: a
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1186–1188
Bloom’s Category: 2. Understanding
7. Commensalism is the type of interaction in which
a. one participant benefits and the other is unaffected.
b. two organisms use the same limited resources.
c. one participant is harmed while the other benefits.
d. one participant is harmed but the other is unaffected.
e. both participants benefit.
Answer: a
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1187
Bloom’s Category: 2. Understanding
8. Amensalism is the type of interaction in which
a. one participant benefits and the other is unaffected.
b. two organisms use the same limited resources.
c. one participant is harmed while the other benefits.
d. one participant is harmed but the other is unaffected.
e. both participants benefit.
Answer: d
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1187
Bloom’s Category: 2. Understanding
9. Reciprocal adaptations are
a. less likely to arise when an increase in dependency on a partner provides an increase in
the benefits realized from the interaction.
b. most likely to arise when an decrease in dependency on a partner provides an increase
in the benefits realized from the interaction.
c. less likely to arise when an increase in dependency on a partner provides a decrease in
the benefits realized from the interaction.
d. most likely to arise when an increase in dependency on a partner provides an increase
in the benefits realized from the interaction.
e. None of the above
Answer: d
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1188
Bloom’s Category: 2. Understanding
10. A series of reciprocal adaptations can lead to what has been dubbed
a. convergent evolution.
b. a tit for tat adaptation.
c. a coevolutionary arms race.
d. a mutualistic relationship.
e. a parasitic relationship.
Answer: c
Textbook Reference: 56.1 What Types of Interactions Do Ecologists Study?
Page: 1188
Bloom’s Category: 2. Understanding
11. Chemically defended animals often advertise their toxicity with _______, which is a
_______.
a. aposematism; warning coloration
b. mimicry; type of camouflage
c. aposematism; reciprocal adaptation
d. crypsis; warning coloration
e. crypsis; mimicry
Answer: a
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1189
Bloom’s Category: 2. Understanding
12. Homotypy is
a. a way of classifying organisms based on phenotype.
b. a method of camouflage that allows an organism to resemble objects their predators
consider toxic or harmful.
c. a method of chemical evasion employed by some insects.
d. All of the above
e. None of the above
Answer: b
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1190
Bloom’s Category: 2. Understanding
13. Most known parasitic relationships involve parasites with nonlethal effects on their
hosts. The most likely explanation for this is that
a. parasitic tactics that have lethal effects are energetically expensive for the parasite.
b. parasitic tactics that have lethal effects are complex and require more time to evolve.
c. parasites are more likely to be successful when their hosts survive.
d. parasites that kill their hosts are less likely to be detected.
e. None of the above
Answer: c
Textbook Reference: 56.2 How Do Antagonistic Interventions Evolve?
Page: 1192–1193
Bloom’s Category: 2. Understanding
14. Many microparasites, in the process of acquiring nutrients at the expense of their
host, cause symptoms of disease. These parasites are known as
a. pathogens.
b. antigens.
c. microgens.
d. allergens.
e. virions.
Answer: a
Textbook Reference: 56.2 How Do Antagonistic Interactions Evolve?
Page: 1193
Bloom’s Category: 2. Understanding
15. What can you conclude about diffuse coevolution by examining the data in Table
56.1?
a. The evolution of similar traits has occurred in suites of species experiencing similar
selection pressures.
b. The depth and width of a flower can restrict the size and shape of the pollinator
mouthparts that can gain access to their nectar.
c. Most flowers can be successfully pollinated by a number of different animal species.
d. Plants not only need to attract pollinators, but must also ensure that those pollinators
carry their pollen to other members of the same species.
e. Both a and c
Answer: b
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1194–1195
Bloom’s Category: 4. Analyzing
16. How are pollinator-plant interactions different from frugivore-fruit interactions?
a. Plant-pollen interactions only benefit the plant.
b. Frugivore-fruit interactions do not always benefit the plant, while plant-pollen
interactions benefit both.
c. Frugivore-fruit interactions always benefit the plant and the frugivore.
d. Plant-pollen interactions benefit both organisms.
e. There are no specific differences.
Answer: b
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1194–1196
Bloom’s Category: 2. Understanding
17. Figure 56.14 details an experiment designed to understand the relationship between
Acacia cornigera trees and Pseudomyrmex ants. What can you conclude from the data in
the bar graphs?
a. The ants provide protection from herbivorous predators.
b. The trees provide protection from predators for the ants.
c. They have an antagonistic relationship.
d. The ants are parasitic to the trees.
e. They have an altruistic relationship.
Answer: a
Textbook Reference: 56.3 How Do Mutualistic Interactions Evolve?
Page: 1197
Bloom’s Category: 4. Analyzing
18. Competition may lead to _______, in which morphological attributes of a species
vary geographically depending on whether a competitor is present or absent.
a. mutualism
b. parasitism
c. altruism
d. character displacement
e. crypsis
Answer: d
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1199
Bloom’s Category: 2. Understanding
19. Although a species might be physiologically able to live under a wide range of
resource conditions, competitors may restrict its use of resources in a particular location.
This is known as
a. mutualism.
b. interference competition.
c. fundamental niche.
d. realized niche.
e. character displacement.
Answer: d
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1200
Bloom’s Category: 2. Understanding
20. What conclusions can you draw about interspecific competition by examining Figure
56.16?
a. Interspecific competition with rock barnacles allows for both rock barnacles and
stellate barnacles to inhabit the same area.
b. Interspecific competition causes the stellate barnacles to grow more slowly than they
would normally.
c. Interspecific competition with rock barnacles restricts stellate barnacles to a smaller
portion of the intertidal zone.
d. Interspecific competition causes the rock barnacles to grow more slowly than they
would normally.
e. Interspecific competition causes the stellate barnacles to grow more slowly than they
would normally.
Answer: c
Textbook Reference: 56.4 What Are the Outcomes of Competition?
Page: 1200
Bloom’s Category: 4. Analyzing