Deck 54: Community Ecology

Question 1

Competitive exclusion is a result of:

A) interspecific competition.
B) intraspecific competition.
C) character displacement.
D) succession.
E) community complexity.

Answer 1

A

Question 2

Habitat is best described as:

A) the local environment in which a species lives.
B) what a species eats.
C) what competes with a species.
D) the abiotic components of a species' environment.
E) the totality of adaptations by a species to its environment.

Answer 2

A

Question 3

A(n) ____ has both biotic and abiotic components.

A) population
B) community
C) ecosystem
D) species
E) genus

Answer 3

C

Question 4

Figure 54-1 In Experimental Condition 2 of the accompanying figure, the distribution of Chthamalus suggests that:

A) interspecific competition kept Chthamalus from extending lower into the intertidal area.
B) intraspecific competition kept Chthamalus from extending lower into the intertidal area.
C) a limiting factor kept Chthamalus from extending lower into the intertidal area.
D) a barnacle parasite kept Chthamalus from extending lower into the intertidal area.
E) predation kept Chthamalus from extending lower into the intertidal area.

Question 5

The realized niche for the green anole was determined by:

A) a limiting resource.
B) competition.
C) symbiosis.
D) coevolution.
E) disease.

Question 6

The community found on a rotting log would include:

A) sunlight.
B) rainwater.
C) bacteria.
D) gases.
E) minerals.

Question 7

Which of the following could be an example of a limiting resource?

A) genetic mutations
B) plenty of nesting sites
C) amount of precipitation
D) abundant food
E) growth rate

Question 8

An organism's role within the structure and function of a particular community is its:

A) habitat.
B) trophic level.
C) population.
D) ecological niche.
E) competition.

Question 9

Niches apply to:

A) individual organisms.
B) individual species.
C) groups of species.
D) communities.
E) ecosystems.

Question 10

The associated figure provides support for which of the following processes?

A) secondary succession
B) competitive exclusion
C) coevolution
D) mutualism
E) resource partitioning

Question 11

One reason that the realized niche and fundamental niche are not typically the same is:

A) limiting resources.
B) reproductive potential.
C) extinction event.s
D) species diversity.
E) species sparsity.

Question 12

Figure 54-1 In Experimental Condition 1 of the accompanying figure, the distribution of Balanus suggests: that

A) interspecific competition kept Balanus from extending higher into the intertidal area.
B) intraspecific competition kept Balanus from extending higher into the intertidal area.
C) an unfavorable environmental factor kept Balanus from extending higher into the intertidal area.
D) Balanus is less motile than Chthamalus .
E) Balanus is more motile than Chthamalus .

Question 13

Which scenario best describes facilitation?

A) A species interaction that modifies and enhances the local environment for other species
B) A species interaction that modifies and detracts from the local environment, inhibiting other species
C) An interaction between members of a population that enhances the local environment for other members of the same population
D) An interaction between members of a population that detracts from the local environment, inhibiting other members of the same population
E) A species interaction that enhances the local environment for a previously extant species

Question 14

Resource partitioning may include which of the following?

A) relocating nesting sites
B) feeding at the same time of day
C) eating the same prey
D) overlapping reproductive seasons
E) intraspecific competition

Question 15

A community consists of ____ species in a given area.

A) one
B) two
C) three
D) four
E) all

Question 16

Competition, predation, and ____ are the main types of interactions that occur among species in a community.

A) mutualism
B) consumption
C) reproduction
D) symbiosis
E) parasitism

Question 17

The ____ niche is the broadest role that an organism can potentially have in a community.

A) realized
B) fundamental
C) displaced
D) excluded
E) limited

Question 18

Community ____ is the description and analysis of patterns and processes within a community.

A) structure
B) functioning
C) ecology
D) dynamics
E) association

Question 19

Large-scale experiments conducted in oak forests of the northeastern United States linked bumper acorn crops to booming mouse populations. The conclusion from these experiments is that:

A) increased levels of first trophic level productivity cause an increase in disease vector activities.
B) competition can result in a more limited realized niche.
C) increased levels of first trophic level productivity cause a decrease in disease vector activities.
D) extermination of mouse populations is the most effective way of reducing Lyme disease transmission.
E) potential threat of Lyme disease in human beings is eliminated following a bumper crop of acorns.

Question 20

Which are the three main roles played by organisms in community life?

A) producer, detritivore, decomposer
B) consumer, detritivore. decomposer
C) producer, consumer, decomposer
D) facilitator, decomposer, consumer
E) realized niche, fundamental niche, habitat

Question 21

Animals with chemical defenses are also typically:

A) fast runners.
B) aposematic.
C) small in size.
D) large in size.
E) camouflaged.

Question 22

An example of both chemical protection and coevolution can be seen in:

A) yellow goldenrod spiders and goldenrod.
B) milkweeds and monarch caterpillars.
C) the poison arrow frog and flying insects.
D) coral animals and dinoflagellates.
E) mycorrhizae.

Question 23

The almost complete loss of the American chestnut tree to the chestnut blight fungus had ____ ecological impact on the moderately diverse Appalachian woodlands of which it was formerly a part.

A) little
B) great
C) moderate
D) undetectable
E) detectable

Question 24

Many poisonous snakes share warning colors of red, yellow, and black. This is an example of:

A) Batesian mimicry.
B) mutualism.
C) camouflage.
D) Müllerian mimicry.
E) character displacement.

Question 25

Which organisms may be a keystone species in a tropical rain forest?

A) gray wolves
B) fruit-eating bats
C) poison arrow frogs
D) fig trees
E) fruit-eating monkeys

Question 26

In the studies by David Tilman of the University of Minnesota and John Downing of the University of Iowa, reported in the journal Nature in 1994, they established and monitored 207 plots of Minnesota grasslands for seven years. During the study period, Minnesota's worst drought in 50 years occurred (1987-1988). The ecologists found that those plots with the greatest number of plant species lost ____ ground cover, as measured by dry weight, and recovered faster than species-poor plots.

A) less
B) more
C) no detectable
D) only deciduous
E) detectable

Question 27

A frog that lacks chemical defenses, yet resembles a poison arrow frog, would exhibit:

A) Batesian mimicry.
B) mutualism.
C) camouflage.
D) Müllerian mimicry.
E) epistasis.

Question 28

Keystone species:

A) are always symbionts.
B) are typically not the most abundant species in the community.
C) illustrate secondary succession.
D) always form the base of a food chain.
E) are only found in tropical communities.

Question 29

During ____ between predator and prey species, the predatory species becomes more efficient at catching prey, while the prey species becomes better at escaping predators.

A) character displacement
B) coevolution
C) Batesian mimicry
D) competitive exclusion
E) succession

Question 30

In a parasitic relationship where the host contracts a disease and sometimes dies, the parasite is called a(n):

A) predator.
B) keystone species.
C) mutualistic symbiont.
D) interspecific competitor.
E) pathogen.

Question 31

If you were to study all of the insect-eating birds in a forest, you would see that many birds eat insects, yet you may not see any evidence of competition. What is the most probable explanation?

A) The birds have coevolved.
B) The birds are exhibiting resource partitioning.
C) The birds are exhibiting intraspecific competition only.
D) There is no keystone species in this community.
E) There is not enough species richness to see evidence of competition.

Question 32

Traditionally, most ecologists have assumed that community stability is a consequence of:

A) competition.
B) predation.
C) community complexity.
D) the relative size of realized niches among species.
E) disease.

Question 33

In a lake, a certain native species of zooplankton is found evenly distributed in the water column. After introduction of a different species of zooplankton, the native species is only found in the shallow water zone. This is most likely an illustration of:

A) character displacement.
B) species richness.
C) primary succession.
D) secondary succession.
E) competitive exclusion.

Question 34

Which habitat would be expected to have the greatest species richness?

A) an island
B) a polar habitat
C) an ecotone
D) an agricultural habitat
E) a mountain top

Question 35

Which country would be expected to have the greatest species richness per unit area?

A) Japan
B) United States
C) Brazil
D) Canada
E) New Zealand

Question 36

Mycorrhizae are associations between:

A) coral animals and dinoflagellates.
B) two types of insects.
C) fungi and plant roots.
D) wasps and orchids.
E) epiphytes and rainforest trees.

Question 37

An example of mutualism is:

A) mycorrhizae and epiphytes.
B) epiphytes and tapeworms.
C) monarch and viceroy butterflies.
D) silverfish and army ants.
E) Rhizobium and legumes.

Question 38

Destructive outbreaks of pests are ____ in cultivated fields, which are low-diversity communities, than in natural communities with greater species richness.

A) less common
B) more common
C) equally common
D) most easily prevented
E) rarely occur

Question 39

The relationship between reef-building coral animals and zooxanthellae is classified as:

A) mutualism.
B) commensalism.
C) Batesian mimicry.
D) parasitism.
E) character displacement.

Question 40

The idea that older, more stable habitats have greater species richness than habitats subjected to frequent, widespread disturbances is known as:

A) natural selection.
B) the time hypothesis.
C) island biogeography.
D) the theory of community stability.
E) the disturbance hypothesis.

Question 41

Species diversity is often very high in the region between two distinct communities, known as a(n):

A) ecotone.
B) secondary successional area.
C) primary successional area.
D) fundamental niche.
E) realized niche.

Question 42

Adaptations that exert a strong competitive force on a predator are the result of coevolution.

Question 43

The current concept of a climax community states that forest communities:

A) never reach a state of permanent equilibrium.
B) never are disturbed.
C) are determined solely by climate.
D) are not permanently affected by fires or floods.
E) are the inevitable end-point of succession.

Question 44

The orderly replacement of one community by another is known as:

A) character displacement.
B) succession.
C) coevolution.
D) the edge effect.
E) competitive exclusion.

Question 45

Figure 54-2 Use the accompanying figure to summarize the key concepts relating to species richness from studies of birds in the South Pacific islands. Each dot in the figure represents an island.

Question 46

In one sentence, summarize the intermediate disturbance hypothesis.

Question 47

Within a community, a dominant species may appropriate a disproportionate share of available resources, thus ____ other species.

A) increasing competition with
B) increasing disease transmission with
C) undergrazing
D) outcompeting
E) decreasing disease transmission

Question 48

Discuss coevolution as it relates to predator-prey interactions. Include a brief discussion of two specific examples.

Question 49

The potential ecological niche of a species is its realized niche.

Question 50

Explain the ecological significance of limiting resources, using three specific examples in your discussion.

Question 51

Primary succession may be seen:

A) on new lava or on sand dunes.
B) after a fire.
C) when farmland is abandoned.
D) only in tropical rain forests.
E) in any community that has periodic disturbances.

Question 52

The species richness of high-latitude communities is ____ compared with that of low-latitude communities.

A) low
B) high
C) no different
D) more dense
E) complex

Question 53

Ecologist James H. Brown of the University of New Mexico has addressed species composition and richness in experiments conducted since 1977 in the Chihuahuan desert of southeastern Arizona. In one experiment, the removal of three dominant species, all kangaroo rats, from several plots resulted in an increased diversity of other rodent species. This increase was ascribed both to lowered competition for food and also to an altered habitat, because the abundance of grass species ____ after the removal of the kangaroo rats.

A) increased
B) decreased
C) did not change
D) was threatened
E) shrunk

Question 54

Species richness is ____ when any one species enjoys a position of dominance.

A) no different
B) more dense
C) reduced
D) increased
E) complex

Question 55

Competition between species 1 and species 2 is beneficial for species 1 and harmful for species 2.

Question 56

Which habitat would most likely have the greatest species richness?

A) prairie
B) savanna
C) tundra
D) temperate desert
E) tropical rain forest

Question 57

____ begins in an area where there was a preexisting community and well-formed soil.

A) Character displacement
B) Species richness
C) Primary succession
D) Secondary succession
E) Competitive exclusion

Question 58

Pollution affects species diversity, thus the species richness of a highly polluted stream is ____ compared with that of a nearby pristine stream.

A) low
B) high
C) no different
D) more dense
E) complex

Question 59

Explain Gleason's individualistic model describing community structure.

Question 60

In which of the following habitat types would species diversity be expected to be relatively low?

A) high environmental stress
B) low environmental stress
C) continental ecosystems
D) ecotones
E) mature successional communities

Question 64

In an ecosystem's bottom-up processes, predators affect the abundances of other populations in the ecological community.
____________________

Question 65

The association of nitrogen fixing bacteria of the genus Rhizobium with legumes such as peas is an example of mutualism.

Question 66

Humans have small mites that live in hair follicles and oil glands around the nose and eyelashes. What would you need to know to classify them as exhibiting mutualism, commensalism, or parasitism?

Question 67

The impact of a keystone species is proportionate to their abundance in an ecosystem.

Question 68

Species richness is a measure of both the number of species and the relative importance of each species based on its abundance, productivity, or size.

Question 69

Describe the factors that affect species richness. Describe the parameters that would probably result in an environment with the greatest possible species richness. Knowing what you do about the tropical rain forests, do they meet these expected parameters?

Question 70

Describe the ongoing research concerning the relationship between species richness and community stability. What research supports or fails to support this relationship?

Question 71

Nicotine synthesis is a(n) adaptation of plant chemical defense against insects.

Question 72

In Müllerian mimicry a defenseless species is protected by its resemblance to a dangerous species.

Question 73

Cryptic coloration advertises a species unpalatability to potential predators.