05 Ecology, Biosphere, Global Change

Question 1

ʺHow does the foraging of animals on tree seeds affect the distribution and abundance of the trees?ʺ This question

A) would require an elaborate experimental design to answer.
B) is difficult to answer because a large experimental area would be required.
C) is difficult to answer because a long-term experiment would be required.
D) is a question that a present-day ecologist would be likely to ask.
E) A, B, C and D are correct.

Answer 1

E) A, B, C and D are correct.

Question 2

Ecology as a discipline directly deals with all of the following levels of biological organization except

A) population.
B) cellular.
C) organismal.
D) ecosystem.
E) community.

Answer 2

B) cellular.

Question 3

Which of the following statements about ecology is incorrect?

A) Ecologists may study populations and communities of organisms.
B) Ecological studies may involve the use of models and computers.
C) Ecology is a discipline that is independent from natural selection and evolutionary history.
D) Ecology spans increasingly comprehensive levels of organization, from individuals to ecosystems.
E) Ecology is the study of the interactions between biotic and abiotic aspects of the environment.

Answer 3

C) Ecology is a discipline that is independent from natural selection and evolutionary history.

Question 4

Which of the following levels of organization is arranged in the correct sequence from most to least inclusive?

A) community, ecosystem, individual, population
B) ecosystem, community, population, individual
C) population, ecosystem, individual, community
D) individual, population, community, ecosystem
E) individual, community, population, ecosystem

Answer 4

B) ecosystem, community, population, individual

Question 5

You are working for the Environmental Protection Agency and researching the effect of a potentially toxic chemical in drinking water. There is no documented scientific evidence showing that the chemical is toxic, but many suspect it to be a health hazard. Using the precautionary principle, what would be a reasonable environmental policy?

A) Establish no regulations until there are conclusive scientific studies.
B) Set the acceptable levels of the chemical conservatively low, and keep them there unless future studies show that they can be safely raised.
C) Set the acceptable levels at the highest levels encountered, and keep them there unless future studies demonstrate negative health effects.
D) Caution individuals to use their own judgment in deciding whether to drink water from a potentially contaminated area.
E) Establish a contingency fund to handle insurance claims in the event that the chemical turns out to produce negative health effects.

Answer 5

B) Set the acceptable levels of the chemical conservatively low, and keep them there unless future studies show that they can be safely raised.

Question 6

Which statement best contrasts environmentalism with ecology?

A) Ecology is the study of the environment; environmentalism is the study of ecology.
B) Ecology provides scientific understanding of living things and their environment; environmentalism is more about conservation and preservation of life on Earth.
C) Environmentalists are only involved in politics and advocating for protecting nature; ecologists are only involved in scientific investigations of the environment.
D) Ecologists study organisms in environments that have been undisturbed by human activities; environmentalists study the effects of human activities on organisms.
E) Environmentalism is devoted to applied ecological science; ecology is concerned with basic/theoretical ecological science.

Answer 6

B) Ecology provides scientific understanding of living things and their environment; environmentalism is more about conservation and preservation of life on Earth.

Question 7

Of the following examples of ecological effect leading to an evolutionary effect (→), which is most correct?

A) When seeds are not plentiful → trees produce more seeds.
B) A few organisms of a larger population survive a drought → these survivors then emigrate to less arid environments.
C) A few individuals with denser fur survive the coldest days of an ice age → the reproducing survivors all have long fur.
D) Fish that swim the fastest in running water → catch the most prey and more easily escape predation.
E) The insects that spend the most time exposed to sunlight → have the most mutations.

Answer 7

C) A few individuals with denser fur survive the coldest days of an ice age → the reproducing survivors all have long fur.

Question 8

Landscape ecology is best described as the study of

A) the flow of energy and materials between the biotic and abiotic components of an ecosystem.
B) how the structure and function of species enable them to meet the challenges of their environment.
C) what factors affect the structure and size of a population over time.
D) the interactions between the different species that inhabit and ecosystem.
E) the factors controlling the exchanges of energy, materials, and organisms among ecosystem patches.

Answer 8

E) the factors controlling the exchanges of energy, materials, and organisms among ecosystem patches.

Question 9

Which of the following are important biotic factors that can affect the structure and organization of biological communities?

A) precipitation, wind
B) nutrient availability, soil pH
C) predation, competition
D) temperature, water
E) light intensity, seasonality

Answer 9

C) predation, competition

Question 10

Which of the following abiotic factors has the greatest influence on the metabolic rates of plants and animals?

A) water
B) wind
C) temperature
D) rocks and soil
E) disturbances

Answer 10

C) temperature

Question 11

There are more species in tropical areas than in places farther from the equator. This is probably a result of

A) fewer predators.
B) more intense annual isolation.
C) more frequent ecological disturbances.
D) fewer agents of disease.
E) all of the above

Answer 11

B) more intense annual isolation.

Question 12

The feeding relationships among the species in a community determine the communityʹs

A) secondary succession.
B) ecological niche.
C) trophic structure.
D) species-area curve.
E) species richness.

Answer 12

C) trophic structure.

Question 13

The principle of competitive exclusion states that

A) two species cannot coexist in the same habitat.
B) competition between two species always causes extinction or emigration of one species.
C) competition in a population promotes survival of the best-adapted individuals.
D) two species that have exactly the same niche cannot coexist in a community.
E) two species will stop reproducing until one species leaves the habitat.

Answer 13

D) two species that have exactly the same niche cannot coexist in a community.

Question 14

Keystone predators can maintain species diversity in a community if they

A) competitively exclude other predators.
B) prey on the communityʹs dominant species.
C) allow immigration of other predators.
D) reduce the number of disruptions in the community.
E) prey only on the least abundant species in the community.

Answer 14

B) prey on the communityʹs dominant species.

Question 15

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.
E) most producers are inedible.

Answer 15

C) most of the energy in a trophic level is lost as it passes to the next higher level.

Question 16

Based on the intermediate disturbance hypothesis, a communityʹs species diversity is

A) increased by frequent massive disturbance.
B) increased by stable conditions with no disturbance.
C) increased by moderate levels of disturbance.
D) increased when humans intervene to eliminate disturbance.
E) increased by intensive disturbance by humans.

Answer 16

C) increased by moderate levels of disturbance.

Question 17

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) biodiversity increases as evapotranspiration decreases.
E) tropical regions have very high rates of immigration and very low rates of extinction.

Answer 17

B) tropical regions generally have more available water and higher levels of solar radiation.

Question 18

Which of the following interactions can correctly be labeled coevolution?

A) the tendency of coyotes to respond to human habitat encroachment by including pet dogs and cats in their diets
B) a genetic change in a virus that allows it to exploit a new host, which responds to virus-imposed selection by changing its genetically controlled habitat preferences
C) a genetic change in foxes that allows them to tolerate human presence (and food)
D) the adaptation of cockroaches to human habitation
E) the ability of rats to survive in a variety of novel environments

Answer 18

B) a genetic change in a virus that allows it to exploit a new host, which responds to virus-imposed selection by changing its genetically controlled habitat preferences

Question 19

Which of the following types of species interaction is correctly paired with its effects on the density of the two interacting populations?

A) predation: as one increases, the other increases
B) parasitism: both decrease
C) commensalism: as one increases the other stays the same
D) mutualism: both decrease
E) competition: both increase

Answer 19

C) commensalism: as one increases the other stays the same

Question 20

During the course of the formation of a parasite/host relationship, a critical first step in this evolution would be

A) changing the behavior of the host or intermediate host.
B) developing asexual reproduction.
C) deriving nourishment without killing the host.
D) starting as an ectoparasite and then later becoming an endoparasite.
E) utilizing both heterotropic and autotrophic nutrition during dormancy.

Answer 20

C) deriving nourishment without killing the host.

Question 21

Community ecologists would consider which of the following to be most significant in understanding the structure of an ecological community?

A) determining how many species are present overall
B) which particular species are present
C) the kinds of interactions that occur among organisms of different species
D) the relative abundance of species
E) all of the above

Answer 21

E) all of the above

Question 22

Which of the following studies would a community ecologist undertake to learn about competitive interactions?

A) selectivity of nest sites among cavity nesting songbirds
B) the grass species preferred by grazing pronghorn antelope and bison
C) nitrate and phosphate uptake by various species of hardwood forest tree species
D) stomach analysis of brown trout and brook trout in streams where they coexist
E) All of the above would be appropriate studies of competitive interaction.

Answer 22

E) All of the above would be appropriate studies of competitive interaction.

Question 23

With a few exceptions, most of the food chains studied by ecologists have a maximum of how many links?

A) 2
B) 3
C) 5
D) 10
E) 15

Answer 23

C) 5

Question 24

Approximately how many kg of carnivore production can be supported by a field plot containing 2000 kg of plant material?

A) 20,000
B) 2,000
C) 200
D) 20
E) 2

Answer 24

D) 20

Question 25

The energetic hypothesis and dynamic stability hypothesis are explanations to account for

A) plant defenses against herbivores.
B) the length of food chains.
C) the evolution of mutualism.
D) resource partitioning.
E) the competitive exclusion principle.

Answer 25

B) the length of food chains.

Question 26

In a tide pool, 15 species of invertebrates were reduced to eight after one species was removed. The species removed was likely a(n)

A) community facilitator.
B) keystone species.
C) herbivore.
D) resource partitioner.
E) mutualistic organism.

Answer 26

B) keystone species.

Question 27

Biomanipulation can best be described as

A) removing many of the next higher trophic level organisms so that the struggling trophic level below can recover.
B) a means of reversing the effects of pollution by applying antidote chemicals that have a neutralizing effect on the community.
C) an example of how one would use bottom-up model for ecosystem restoration.
D) adjusting the population numbers of each of the trophic levels back to the numbers that they were before man started disturbing ecosystems.
E) monitoring and adjusting the nutrient and energy flow through a community with new technologies.

Answer 27

A) removing many of the next higher trophic level organisms so that the struggling trophic level below can recover.

Question 28

You are most likely to observe primary succession in a terrestrial community when you visit a(n)

A) tropical rain forest.
B) abandoned field.
C) recently burned forest.
D) recently created volcanic island.
E) recently plowed field.

Answer 28

D) recently created volcanic island.