Campbell Biology in Focus, 2e (Urry)
Chapter 43 Global Ecology and Conservation Biology
43.1 Multiple-Choice Questions
1) Which of the following ecological locations, if destroyed, would result in the greatest loss of
species diversity?
A) tundra
B) deciduous forests
C) tropical rain forest
D) grasslands
E) islands
2) 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.
3) 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.
4) 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
5) 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 higher than background extinction rates.
D) current extinction is primarily affecting plant diversity.
6) Which of the following terms includes all of the others?
A) species diversity
B) biodiversity
C) genetic diversity
D) ecosystem diversity
E) species richness
7) 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) endangered species are mainly tropical.
D) only endangered species are vertebrates.
8) What is our innate appreciation of wild environments and living organisms called?
A) biodiversity
B) overharvesting
C) biophilia
D) conservation
E) landscape ecology
9) 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
10) According to the International Union for Conservation of Nature and Natural Resources
(IUCN), 73% of species have become extinct, endangered, vulnerable, or rare because of
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.
11) 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.
12) Overharvesting 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.
13) 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) Flying foxes protect trees from herbivores.
B) Flying foxes are increasingly hunted as a luxury food.
C) Flying foxes spread disease between trees in a population.
D) Flying foxes pollinate tree flowers and disperse seeds.
14) 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 example of 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.
15) 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) lack of regulations to limit the harvest of the medicinal plant ginseng
D) constructing oil and gas pipelines through old growth forest
16) Which of the following species was driven to extinction by overharvesting by
hunters/fishermen?
A) African elephant
B) the great auk
C) North American bluefin tuna
D) flying foxes
E) American bison
17) The wood turtle (Glyptemys insculpta) is a small, long-lived turtle that is endangered through
much of its range in North America. As their populations shrink in size, it becomes even more
difficult for turtles to find mates, and small populations have steadily become smaller. What best
describes what the wood turtles in small populations are experiencing?
A) overharvesting
B) an extinction vortex
C) habitat loss
D) climate change
18) Which of the following conditions is the most likely indicator of a population in an
extinction vortex?
A) The population is geographically divided into many populations.
B) The species in question is found only in small, stable 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 connected only by corridors.
19) Review the formula for effective population size: Ne = . 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
20) 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.
21) Which of the following can potentially influence effective population size (Ne)?
A) length of life span after reproduction
B) body size of individuals
C) number of alleles per trait
D) amount of gene flow between geographically separated populations
22) 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) altering habitat to be more suitable for a rare bird species
D) maintaining optimum size of all populations in the ecosystem
23) 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) D-PA would likely involve bringing together individuals from scattered small populations to
interbreed in order to promote genetic diversity.
C) S-PA would investigate and eliminate all of the human impacts on the habitat of the species
being studied for recovery.
D) D-PA would use recently collected population data to calculate an effective population size.
24) Managing southeastern forests specifically for the red-cockaded woodpecker
A) required the growth of a dense understory of trees and shrubs.
B) included providing nesting cavities for breeding groups.
C) caused other species of songbird to decline.
D) involved strict fire-suppression measures.
E) involved the creation of fragmented forest habitat.
25) 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 forest-adapted species disappear,
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 species diversity to increase because of the new
habitats created.
26) According to the small-population approach, what would be the best strategy for saving a
population from extirpation?
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
27) Relatively small geographic areas with high concentrations of endemic species and a large
number of endangered and threatened species are known as
A) nature reserves.
B) movement corridors.
C) biodiversity hot spots.
D) extinction vortices.
28) 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.
29) Brown-headed 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.
30) Which of the following is consistent with forest fragmentation research?
A) The number of species 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) Landscapes dominated by small forest fragments support more species than continuous forest.
31) 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.
32) 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 the abiotic factors present, not the biotic factors.
E) designated hot spots change on a daily basis.
33) The success with which plants extend their range northward following glacial retreat is best
determined by
A) whether there is simultaneous migration of herbivores.
B) their tolerance to shade.
C) their seed dispersal rate.
D) their size.
E) their growth rate.
34) As the climate changes because of global warming, species’ ranges of plants in the Northern
Hemisphere may move northward, using effective reproductive adaptations to disperse their
seeds. The trees that are most likely to avoid extinction in such an environment are those that
A) have seeds that are easily dispersed by wind or animals.
B) have seeds that sprout quickly.
C) produce seeds that contain large nutrient stores for growth.
D) have seeds that become viable only after a forest fire.
E) disperse many seeds in close proximity to the parent tree.
35) If global warming continues at its present rate, which biomes will likely take the place of the
coniferous forest (taiga)?
A) tundra and polar ice
B) temperate broadleaf forest and grassland
C) tropical forest and savanna
D) tropical and temperate broadleaf forest
36) Which of the following investigations would shed the most light on the future distribution of
organisms in temperate regions that are faced with climate change?
A) Remove, to the mineral soil, all of the organisms from an experimental plot and monitor the
colonization of the area over time in terms of both species diversity and abundance.
B) Look at the climatic changes that occurred since the last ice age and how species redistributed
as glaciers melted, then make predictions on future distribution in species based on past trends.
C) Quantify the impact of humankind’s activities on present-day populations of threatened and
endangered species to assess the rate of extirpation and extinction.
D) There is no scientific investigation that can help make predictions on the future distribution of
organisms.
37) Burning fossil fuels releases oxides of sulfur and nitrogen. These air pollutants can be
responsible for
A) the increase of fish populations in lakes.
B) precipitation with a pH as low as 3.0.
C) biological magnification of toxins.
D) preventing eutrophication.
38) How can human-caused environmental changes create problems for selecting a site for a
preserve?
A) Nutrient enrichment prevents preserves from being connected by corridors.
B) The environmental conditions of almost any site may change because of climate change.
C) Global warming makes all climates less suitable for maintaining high diversity.
D) Only lands that are not useful to human activities are available for preserves.
39) 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
40) The use of DDT as an insecticide in the United States has been outlawed since 1971, yet it 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.
41) 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.
42) Which of the following refers to the reflecting and absorption of infrared radiation by
atmospheric methane, carbon dioxide, and water?
A) acid precipitation
B) biological magnification
C) greenhouse effect
D) eutrophication
43) What is caused by excessive nutrient runoff into aquatic ecosystems?
A) acid precipitation
B) biological magnification
C) greenhouse effect
D) eutrophication
44) What causes extremely high levels of toxic chemicals in fish-eating birds?
A) acid precipitation
B) biological magnification
C) greenhouse effect
D) eutrophication
45) Considering the most important ecological issue of the future, what is the biggest challenge
that Costa Rica will likely face in its dedication to conservation and restoration in the future?
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