Campbell Biology: Campbell Biology Chapter 56 (powell_h) Flashcards
1) Which of the following ecological locations has the greatest
species diversity?
A) tundra
B) deciduous forests
C)
tropics
D) grasslands
E) islands
Answer: C
2) What is the estimated number of extant species on Earth?
A)
1,000 to 50,000
B) 50,000 to 150,000
C) 500,000 to
1,000,000
D) 10,000,000 to 100,000,000
E) 5 billion to 10 billion
Answer: D
3) Estimates of current rates of extinction
A) indicate that we
have reached a state of stable equilibrium in which speciation rates
equal extinction rates.
B) suggest that one-half of all animal
and plant species may be gone by the year 2100.
C) indicate that
rates may be greater than the mass extinctions at the close of the
Cretaceous period.
D) indicate that only 1% of all of the
species that have ever lived on Earth are still alive.
E)
suggest that rates of extinction have decreased globally.
Answer: C
4) Extinction is a natural phenomenon. It is estimated that 99% of
all species that ever lived are now extinct. Why then do we say that
we are now experiencing an extinction (loss of biodiversity) crisis?
A) Humans are ethically responsible for protecting endangered
species.
B) Scientists have finally identified most of the
species on Earth and are thus able to quantify the number of species
becoming extinct.
C) The current rate of extinction is high and
human activities threaten biodiversity at all levels.
D) Humans
have greater medical needs than at any other time in history, and many
potential medicinal compounds are being lost as plant species become
extinct.
E) Most biodiversity hot spots have been destroyed by
recent ecological disasters.
Answer: C
5) Which of the following provides the best evidence of a
biodiversity crisis?
A) the incursion of a non-native species
B) increasing pollution levels
C) decrease in regional
productivity
D) high rate of extinction
E) climate change
Answer: D
6) Although extinction is a natural process, current extinctions are
of concern to environmentalists because
A) more animals than
ever before are going extinct.
B) most current extinctions are
caused by introduced species.
C) the rate of extinction is
unusually high.
D) current extinction is primarily affecting
plant diversity.
E) None of the options are correct.
Answer: C
7) Which of the following terms includes all of the others?
A)
species diversity
B) biodiversity
C) genetic diversity
D) ecosystem diversity
E) species richness
Answer: B
8) According to the U.S. Endangered Species Act (ESA), the difference
between an endangered species and a threatened one is that
A) an
endangered species is closer to extinction.
B) a threatened
species is closer to extinction.
C) threatened species are
endangered species outside the U.S. borders.
D) endangered
species are mainly tropical.
E) only endangered species are vertebrates.
Answer: A
9) Which of the following groups is most threatened by global
extinctions?
A) mammals
B) birds
C) fish
D)
amphibians
E) plants
Answer: D
10) To better comprehend the magnitude of current extinctions, it
will be necessary to
A) monitor atmospheric carbon dioxide
levels more closely.
B) differentiate between plant extinction
and animal extinction numbers.
C) focus on identifying more
species of mammals and birds.
D) identify more of the yet
unknown species of organisms on Earth.
E) use the average
extinction rates of vertebrates as a baseline.
Answer: D
11) What term did E. O. Wilson coin for our innate appreciation of
wild environments and living organisms?
A) bioremediation
B) bioethics
C) biophilia
D) biophobia
E)
landscape ecology
Answer: C
12) We should care about loss in biodiversity in the populations of
other species because of
A) biophilia.
B) potential loss
of medicines and other products yet undiscovered from threatened
species.
C) potential loss of genes, some of which may code for
proteins useful to humans.
D) the risk to global ecological
stability.
E) All of the options are correct.
Answer: E
13) The most serious consequence of a decrease in global biodiversity
would be the
A) increase in global warming and thinning of the
ozone layer.
B) potential loss of ecosystem services on which
people depend.
C) increase in the abundance and diversity of
edge-adapted species.
D) loss of source of genetic diversity to
preserve endangered species.
E) loss of species for "bioprospecting."
Answer: B
14) Which of the following is the most direct threat to biodiversity?
A) increased levels of atmospheric carbon dioxide
B) the
depletion of the ozone layer
C) overexploitation of selected
species
D) habitat destruction
E) zoned reserves
Answer: D
15) According to most conservation biologists, the single greatest
threat to global biodiversity is
A) chemical pollution of water
and air.
B) stratospheric ozone depletion.
C)
overexploitation of certain species.
D) alteration or
destruction of the physical habitat.
E) global climate change
resulting from a variety of human activities.
Answer: D
16) What is the biological significance of genetic diversity between
populations?
A) Genes for adaptive traits to local conditions
make microevolution possible.
B) The population that is most fit
would survive by competitive exclusion.
C) Genetic diversity
allows for species stability by preventing speciation.
D)
Isolated populations become more fit.
E) Diseases and parasites
are not spread between separated populations.
Answer: A
17) Introduced species can have deleterious effects on biological
communities by
A) preying on native species.
B) competing
with native species for food or light.
C) displacing native
species.
D) competing with native species for space or
breeding/nesting habitat.
E) All of the options are correct.
Answer: E
18) Overexploitation encourages extinction and is most likely to
affect
A) animals that occupy a broad ecological niche.
B)
large animals with low intrinsic reproductive rates.
C) most
organisms that live in the oceans.
D) terrestrial organisms more
than aquatic organisms.
E) edge-adapted species.
Answer: B
19) How might the extinction of some Pacific Island bats called
"flying foxes" threaten the survival of over 75% of the tree
species in those islands?
A) The bats eat the insects that harm
competitor plants.
B) The bats consume the fruit including the
seeds that would disrupt the trees' reproductive cycle.
C) The
bats roost in the trees and fertilize soil around the trees with their
nitrogen-rich droppings.
D) The bats pollinate the trees and
disperse seeds.
E) The bats pierce the fruit, which allows the
seeds to germinate.
Answer: D
20) The greatest cause of the biodiversity crisis, the one which
includes all of the others, is
A) pollution.
B) global
warming.
C) habitat destruction.
D) introduced species.
E) human overpopulation.
Answer: E
21) Of the following ecosystem types, which have been impacted the
most by humans?
A) wetland and riparian
B) open and
benthic ocean
C) desert and high alpine
D) taiga and
second-growth forests
E) tundra and arctic
Answer: A
22) The introduction of the brown tree snake in the 1940s to the
island of Guam has resulted in
A) eradication of non-native rats
and other undesirable/pest species.
B) the extirpation of many
of the island's bird and reptile species.
C) a good lesson in
biological control.
D) a new species of hybrids from
crossbreeding with a native snake species.
E) its failure to
compete with native species and its quick elimination from the island.
Answer: B
23) Which of the following examples poses the greatest potential
threat to biodiversity?
A) replanting, after a clear cut, a
monoculture of Douglas fir trees on land that consisted of old-growth
Douglas fir, western cedar, and western hemlock
B) allowing
previously used farmland to go fallow and begin to fill in with weeds
and then shrubs and saplings
C) trapping and relocating large
predators, such as mountain lions, that pose a threat as they move
into areas of relatively dense human populations
D) importing an
Asian insect into the United States to control a weed that competes
with staple crops
E) releasing sterilized rainbow trout to boost
the sport fishing of a river system that contains native brook trout
Answer: D
24) Which of the following is a type of research in which a
conservation biologist would be involved?
A) reestablishing
whooping cranes in their former breeding grounds in North Dakota
B) studying species diversity and interaction in the Florida
Everglades, past and present
C) studying population ecology of
grizzly bears in Yellowstone National Park
D) determining the
effects of hunting white-tailed deer in Vermont
E) determining
the effect of protection programs on the recovery of the North
Atlantic cod fishery
Answer: A
25) Which of the following conditions is the most likely indicator of
a population in an extinction vortex?
A) The population is
geographically divided into smaller populations.
B) The species
in question is found only in small pockets of its former range.
C) The effective population size of the species falls below 500.
D) Genetic measurements indicate a loss of genetic variation
over time.
E) The population is no longer connected by corridors.
Answer: D
26) According to the small-population approach, what would be the
best strategy for saving a population that is in an extinction vortex?
A) determining the minimum viable population size by taking into
account the effective population size
B) establishing a nature
reserve to protect its habitat
C) introducing individuals from
other populations to increase genetic variation
D) determining
and remedying the cause of its decline
E) reducing the
population size of its predators and competitors
Answer: C
27) Review the formula for effective population size. Imagine a
population of 1,000 small rodents. Of these, 300 are breeding females,
300 are breeding males, and 400 are nonbreeding juveniles. What is the
effective population size?
A) 1,000
B) 1,200
C) 600
D) 400
E) 300
Answer: C
28) If the sex ratio in a population is significantly different from
50:50, then which of the following will always be true?
A) The
population will enter the extinction vortex.
B) The genetic
variation in the population will increase over time.
C) The
genetic variation in the population will decrease over time.
D)
The effective population size will be greater than the actual
population size.
E) The effective population size will be less
than the actual population size.
Answer: E
29) Which of the following life history traits can potentially
influence effective population size (Ne)?
A) maturation age
B) genetic relatedness among individuals in a population
C) family and population size
D) gene flow between
geographically separated populations
E) All of the options are correct.
Answer: E
30) Modern conservation biology increasingly aims at
A)
protecting federally listed endangered species.
B) lobbying for
strict enforcement of the U.S. Endangered Species Act.
C)
sustaining biodiversity of entire ecosystems and communities.
D)
maintaining genetic diversity in all species.
E) saving as much
habitat as possible from development and exploitation.
Answer: C
31) The word triage originated during World War I and was first used
by French doctors in prioritizing patients based on the severity of
their wounds, because there were more wounded soldiers in need of
urgent care than there were resources to treat them. Conservation
biologists have to make similar determinations with degraded
ecosystems. Which of the following is the most important consideration
when it comes to managing for maintenance of biodiversity?
A)
identifying large, high-profile vertebrates first, because steps to
saving them would be most recognized by the public
B)
determining which species is most important for conserving
biodiversity as a whole
C) replanting suitable habitat for fauna
D) assessing the economic costs and the gains for society
E) maintaining optimum size of all populations in the ecosystem
Answer: B
32) Which of the following species was driven to extinction by
overexploitation by hunters/fishermen?
A) African elephant
B) the great auk
C) North American bluefin tuna
D)
flying foxes
E) American bison
Answer: B
33) The primary difference between the small-population approach
(S-PA) and the declining-population approach (D-PA) to biodiversity
recovery is
A) S-PA is interested in bolstering the genetic
diversity of a threatened population rather than the environmental
factors that caused the population's decline.
B) S-PA kicks in
for conservation biologists when population numbers fall below 500.
C) D-PA would likely involve bringing together individuals from
scattered small populations to interbreed in order to promote genetic
diversity.
D) S-PA would investigate and eliminate all of the
human impacts on the habitat of the species being studied for
recovery.
E) D-PA would use recently collected population data
to calculate an extinction vortex.
Answer: A
34) The long-term problem with red-cockaded woodpecker habitat
intervention in the southwest United States is
A) the only
habitat that can support their recovery is large tracts of mature
southern pine forest.
B) the mature pine forests in which they
live cannot ever be subjected to forest fire.
C) all of the
appropriate red-cockaded woodpecker habitat has already been logged or
converted to agricultural land.
D) the social organization of
the red-cockaded woodpecker precludes the dispersal of reproductive
individuals.
E) what habitat remains for the red-cockaded
woodpecker does not contain trees suitable for nest-cavity construction.
Answer: D
35) Managing southwestern forests specifically for the red-cockaded
woodpecker
A) was wholeheartedly supported by the timber
extraction industry.
B) contributed to greater abundance and
diversity of other forest bird species.
C) caused other species
of songbird to decline.
D) involved strict fire suppression
measures.
E) involved the creation of fragmented forest habitat.
Answer: B
36) Which of the following is true about the current research
regarding forest fragmentation?
A) Fragmented forests support a
greater biodiversity because they result in the combination of
forest-edge species and forest-interior species.
B) Fragmented
forests support a lesser biodiversity because the forested-adapted
species leave, and only the edge and open-field species can occupy
fragmented forests.
C) Fragmented forests are the goal of
conservation biologists who design wildlife preserves.
D)
Harvesting timber that results in forest fragmentation results in less
soil erosion.
E) The disturbance of timber extraction causes the
species diversity to increase because of the new habitats created.
Answer: B
37) Relatively small geographic areas with high concentrations of
endemic species and a large number of endangered and threatened
species are known as
A) endemic sinks.
B) critical
communities.
C) biodiversity hot spots.
D) endemic
metapopulations.
E) bottlenecks.
Answer: C
38) How is habitat fragmentation related to biodiversity loss?
A) Less carbon dioxide is absorbed by plants in fragmented
habitats.
B) In fragmented habitats, more soil erosion takes
place.
C) Populations of organisms in fragments are smaller and,
thus, more susceptible to extinction.
D) Animals are forced out
of smaller habitat fragments.
E) Fragments generate silt that
negatively affects sensitive river and stream organisms.
Answer: C
39) Cowbirds utilize fragmented forests effectively by
A)
feeding on the fruits of shrubs that tend to grow at the
forest/open-field interface.
B) parasitizing the nests of forest
birds, and feeding on open-field insects.
C) roosting in forest
trees, and nesting in grassy fields.
D) outcompeting other
songbird species in fragmented communities.
E) using forest
cover to escape from predators in their normal grassland habitat.
Answer: B
40) Which of the following is consistent with forest fragmentation
research?
A) Productivity is the same in both fragmented forests
and forest interiors.
B) Edge communities consistently have low
species diversity.
C) Forest-interior species show declines in
small patch communities.
D) New-edge species that migrate in do
not seem to compete with forest species and often increase
biodiversity in fragmented forests.
E) Species diversity is
always lower in fragmented forests when compared to forest interiors
in the same region.
Answer: C
41) How are movement corridors potentially harmful to certain
species?
A) They increase inbreeding.
B) They promote
dispersion.
C) They spread disease and parasites.
D) They
increase genetic diversity.
E) They allow seasonal migration.
Answer: C
42) Biodiversity hot spots are not necessarily the best choice for
nature preserves because
A) hot spots are situated in remote
areas not accessible to wildlife viewers.
B) their ecological
importance makes land purchase very expensive.
C) a hot spot for
one group of organisms may not be a hot spot for another
group.
D) hot spots are designated by abiotic factors present,
not biotic factors.
E) designated hot spots change on a daily basis.
Answer: C
43) What is the biggest problem with selecting a site for a preserve?
A) There is always a conflict about use of land set aside for
preservation.
B) Making a proper selection is difficult because
currently the environmental conditions of almost any site change so
quickly.
C) Keystone species are difficult to identify in
potential preserve sites.
D) Only lands that are not useful to
human activities are available for preserves.
E) Most of the
best sites are inaccessible by land transportation, so making roads to
them is often prohibitively expensive.
Answer: B
44) Which of the following is true about "hot spots"?
A) One-third of all species on Earth occupy less than 1.5% of
Earth's land area (hot spots).
B) All of the plants and animals
containing genes that may be useful to humankind are located in
Earth's hot spots.
C) Around 75% of all of the undiscovered
species of organisms live in ecological hot spots.
D) As
conservation measures improve over the next ten years, hot spots will
likely disappear.
E) The hot spots that are in most dire need of
remediation are located in the tundra.
Answer: A
45) What is a critical load?
A) the amount of nutrient
augmentation necessary to bring a depleted habitat back to its former
level
B) the level of a given toxin in an ecosystem that is
lethal to 50% of the species present
C) the maximum abundance
level of a particular species, beyond which additional numbers will
degrade a habitat
D) the amount of added nutrient that can be
absorbed by plants without damaging ecosystem integrity
E) the
number of predators an ecosystem can support that effectively culls
prey populations to healthy levels
Answer: D
46) The use of DDT as an insecticide in the United States has been
outlawed since 1971, yet is still a problem for certain top-level
carnivores in the United States. Which of the following choices best
explains this apparent incongruity?
A) DDT is still used for
mosquito control in tropical countries, and certain migratory
predators can be affected by a seasonal biomagnification.
B) DDT
is persistent in the environment and all of the pre-1971 DDT is still
available in toxic form to poison top-level carnivores.
C)
Pre-1971 DDT has been deposited in certain habitats, particularly
wetlands and estuaries, so predators in these ecosystems are
vulnerable to biomagnifications of DDT.
D) Whereas most
DDT-susceptible species have become resistant to persistent DDT,
others are still vulnerable.
E) All of the options are correct.
Answer: A
47) Agricultural lands frequently require nutrient augmentation
because
A) nitrogen-fixing bacteria are not as plentiful in
agricultural soils because of the use of pesticides.
B) the
nutrients that become the biomass of plants are not cycled back to the
soil on lands where they are harvested.
C) land that is
available for agriculture tends to be nutrient-poor.
D) grains
raised for feeding livestock must be fortified, and thus require
additional nutrients.
E) cultivation of agricultural land
inhibits the decomposition of organic matter.
Answer: B
48) Burning fossil fuels releases oxides of sulfur and nitrogen.
These air pollutants can be responsible for
A) the death of fish
in lakes.
B) precipitation with a pH as low as 3.0.
C)
calcium deficiency in soils.
D) direct damage to plants by
leaching nutrients from the leaves.
E) All of the options are correct.
Answer: E
49) This causes an increase in the intensity of UV radiation reaching
Earth.
A) depletion of ozone layer
B) acid precipitation
C) biological magnification
D) greenhouse effect
E) eutrophication
Answer: A
50) This term refers to the reflecting and absorption of infrared
radiation by atmospheric methane, carbon dioxide, and water.
A)
depletion of ozone layer
B) acid precipitation
C)
biological magnification
D) greenhouse effect
E) eutrophication
Answer: D
51) This is caused by excessive nutrient runoff into aquatic
ecosystems.
A) depletion of ozone layer
B) acid
precipitation
C) biological magnification
D) greenhouse
effect
E) eutrophication
Answer: E
52) This causes extremely high levels of toxic chemicals in
fish-eating birds.
A) depletion of ozone layer
B) acid
precipitation
C) biological magnification
D) greenhouse
effect
E) eutrophication
Answer: C
53) The biggest challenge that Costa Rica will likely face in its
dedication to conservation and restoration in the future is
A)
the pressures of its growing population.
B) its small size (as a
country), which may not be able to maintain large enough reserves.
C) the potential for disturbance of sensitive species in
reserves by ecotourists.
D) spread of disease and parasites via
corridors from neighboring countries.
E) the large number of
Costa Rican species already in the extinction vortex.
Answer: A
54) Which of the following nations has become a world leader in the
establishment of zoned reserves?
A) Costa Rica
B) Canada
C) China
D) United States
E) Mexico
Answer: A

55) Based on what you know about ecosystem stability and the
information provided in the graph, which community (A-E) would likely
support the most biodiversity?
A) A
B) B
C) C
D) D
E) E
Answer: A

56) Study the information above about quail habitats. Which of these
represents the best quail habitat in terms of fragmentation and edge?
A) A
B) B
C) C
D) D
E) E
Answer: C

57) Study the information above about quail habitats. Assuming that
only one quail can occupy a habitat where all cover requirements are
met, what is the maximum number of quail that could inhabit any of the
hypothetical plots shown?
A) 1
B) 2
C) 4
D) 6
E) 9
Answer: E

Flycatcher birds that migrate from Africa to Europe feed their
nestlings a diet that is almost exclusively moth caterpillars. The
graph below shows the mean dates of arrival, bird hatching, and peak
caterpillar season for the years 1980 and 2000.
58) The shift in the peak of caterpillar season is most likely
due to
A) pesticide use.
B) earlier migration returns of
flycatchers.
C) an innate change in the biological clock of the
caterpillars.
D) global warming.
E) acid precipitation in Europe.
Answer: D

Flycatcher birds that migrate from Africa to Europe feed their
nestlings a diet that is almost exclusively moth caterpillars. The
graph below shows the mean dates of arrival, bird hatching, and peak
caterpillar season for the years 1980 and 2000.
59) Why were ecologists concerned about the shift in the peak
caterpillar season from June 3, 1980, to May 15, 2000?
A) The
caterpillars would have eaten much of the foliage of the trees where
flycatchers would have nested, rendering their nests more open to
predation.
B) The earlier hatching of caterpillars would compete
with other insect larval forms which the flycatchers would also use to
feed their young.
C) The 2000 flycatcher nestlings would miss
the peak caterpillar season and might not be as well fed.
D) The
flycatchers would have to migrate sooner to match their brood-rearing
to the time of peak caterpillar season.
E) Pesticides, which
have a negative effect on the ecosystem, would have to be used to
control the earlier outbreak of caterpillar hatching.
Answer: C
60) Suppose you attend a town meeting at which some experts tell the
audience that they have performed a cost-benefit analysis of a
proposed transit system that would probably reduce overall air
pollution and fossil fuel consumption. The analysis, however, reveals
that ticket prices will not cover the cost of operating the system
when fuel, wages, and equipment are taken into account. As a
biologist, you know that if ecosystem services had been included in
the analysis the experts might have arrived at a different answer. Why
are ecosystem services rarely included in economic analyses?
A)
Their cost is difficult to estimate and people take them for granted.
B) They are not worth much and are usually not considered.
C) There are no laws that require investigation of ecosystem
services in environmental planning.
D) There are too many
variables to ecosystem services, making their calculation impossible.
E) Ecosystem services only take into account abiotic factors
that affect local environments.
Answer: A
61) Your friend is wary of environmentalists' claims that global
warming could lead to major biological change on Earth. Which of the
following statements can you use in response to your friend's
suspicions?
A) We know that atmospheric carbon dioxide has
increased over the past 150 years.
B) Through measurements and
observations, we know that CO2 levels and temperature fluctuations are
directly correlated, even in prehistoric times.
C) Global
warming could have significant effects on agriculture in the United
States.
D) Sea levels will likely rise, displacing as much as
50% of the world's human population.
E) All statements listed
could be used.
Answer: E
62) One characteristic that distinguishes a population in an
extinction vortex from most other populations is that
A) its
habitat is fragmented.
B) it is a rare, top-level predator.
C) its effective population size is much lower than its total
population size.
D) its genetic diversity is very low.
E)
it is not well adapted to edge conditions.
Answer: D
63) The main cause of the increase in the amount of CO₂ in Earth's
atmosphere over the past 150 years is
A) increased worldwide
primary production.
B) increased worldwide standing crop.
C) an increase in the amount of infrared radiation absorbed by
the atmosphere.
D) the burning of larger amounts of wood and
fossil fuels.
E) additional respiration by the rapidly growing
human population.
Answer: D
64) What is the single greatest threat to biodiversity?
A)
overharvesting of commercially important species
B) introduced
species that compete with native species
C) pollution of Earth's
air, water, and soil
D) disruption of trophic relationships as
more and more prey species become extinct
E) habitat alteration,
fragmentation, and destruction
Answer: E
65) Which of the following is a consequence of biological
magnification?
A) Toxic chemicals in the environment pose
greater risk to top-level predators than to primary consumers.
B) Populations of top-level predators are generally smaller than
populations of primary consumers.
C) The biomass of producers in
an ecosystem is generally higher than the biomass of primary
consumers.
D) Only a small portion of the energy captured by
producers is transferred to consumers.
E) The amount of biomass
in the producer level of an ecosystem decreases if the producer
turnover time increases.
Answer: A
66) Which of the following strategies would most rapidly increase the
genetic diversity of a population in an extinction vortex?
A)
Capture all remaining individuals in the population for captive
breeding followed by reintroduction to the wild.
B) Establish a
reserve that protects the population's habitat.
C) Introduce new
individuals transported from other populations of the same species.
D) Sterilize the least fit individuals in the population.
E) Control populations of the endangered population's predators
and competitors.
Answer: C
67) Of the following statements about protected areas that have been
established to preserve biodiversity, which one is not correct?
A) About 25% of Earth's land area is now protected.
B)
National parks are one of many types of protected areas.
C) Most
protected areas are too small to protect species.
D) Management
of a protected area should be coordinated with management of the land
surrounding the area.
E) It is especially important to protect
biodiversity hot spots.
Answer: A