Deck 58: A Changing Biosphere

Question 1

Two populations of an endangered species exist in separate locations.Population A has 20 individuals.Population B has 200 individuals.Each population undergoes accidental deaths during the year that reduce their respective numbers by 10 percent.Which population, if either, has a greater chance of extinction, and why?

A) Population A, because the loss of two individuals leads to a greater likelihood of demographic stochasticity.
B) Population A, because the loss of two individuals leads to a greater increase in genetic diversity and inbreeding depression.
C) Neither; the populations are equally likely to go extinct because they lost the same percentage of individuals.
D) Population B, because a loss of 20 individuals is much more serious than a loss of only 2.
E) Population B, because a loss of 20 individuals leads to a greater increase in genetic diversity and inbreeding depression.

Answer 1

A

Question 2

Refer to the graph. The graph shows the breakdown by extinction risk category of the species assessed by the International Union for Conservation of Nature (IUCN).Based on the graph, what percentage of species in the world are considered threatened?

A) 10 percent of all species so far assessed
B) 20 percent of all species so far assessed
C) 6 percent of all species in the world
D) 10 percent of all species in the world
E) 20 percent of all species in the world

Answer 2

B

Question 3

Until a few years ago, ivory-billed woodpeckers had not been seen since the 1940s.The species was widely assumed to be extinct.Its habitat in the lowland forests of the southeastern United States had been destroyed by clear cutting.Then, in 2004, two ornithologists thought they spotted an ivory-bill in an Arkansas swamp.These and other ornithologists immediately began a massive search.Several more sightings and a few audio recordings were made, and ornithologists hoped the species was recovering now that forests are regrowing.But skeptics challenged both the sightings and the recordings.No reliable sightings have been made since 2005.Given this information, what conclusion can be drawn about the extinction of the ivory-billed woodpecker?

A) It is probably extinct, since no sightings have been made since 2005.
B) It is probably extinct, since the few sightings were likely of the last survivors.
C) It is not extinct, since it was recently seen and heard by competent ornithologists.
D) Its extinction is not certain, because its swamp forest habitat makes it difficult to track.
E) It will be considered extinct if recent photos and videos cannot be verified by experts.

Answer 3

D

Question 4

Refer to the graph. The IUCN has so far assessed 53,033 species, of the approximately 8.7 million thought to exist on Earth.The graph shows the number of species in each extinction risk category that so far have been assessed.This suggests that, especially in nonvertebrate categories, such as corals, the numbers shown on the graph are likely to be

A) very accurate, because they have been comprehensively assessed.
B) fairly accurate, because even good estimates are subject to some errors.
C) underestimated, because only a small percentage of species have been assessed.
D) underestimated, because there is no valid way to assess aquatic species such as corals.
E) overestimated, because scientists tend to assess invertebrates more closely than vertebrates.

Question 5

Scientists consider amphibians, which die or show signs of stress in degraded environmental conditions, to be biological indicators for all of the following reasons except that they

A) have permeable skin that is easily infected or damaged.
B) live both in water and on land during their life cycles.
C) stay in approximately the same place all their lives.
D) are currently declining at greater rates than are other species.
E) are more adaptable to habitat loss than are other species.

Question 6

Unusually warm waters in the Caribbean caused mass coral bleaching events in 1998, 2005, and 2014-2016 (an unprecedented 3-year barrage of record-breaking temperatures).As many as 80-90 percent of corals were damaged, many died, and more are expected to die.Temperature spikes during these years occurred because of El Niño effects, but the bleaching and its devastating effects on coral were likely worsened by ongoing

A) natural predation loss.
B) overharvesting.
C) habitat loss and degradation.
D) climate change.
E) vandalism of reefs by humans.

Question 7

Australia's Lord Howe Island stick insect was believed to have become extinct about 1930.Accidentally introduced mice and rats were thought to have eliminated it from its only known habitat.The enormous 12-cm-long insect was rediscovered in 2001 when scientists found 24 individuals living underneath a single shrub on the world's tallest volcanic sea stack, an extremely isolated islet in the Pacific called Ball's Pyramid.This set of facts exemplifies that

A) extinction cannot be easily confirmed.
B) extinction can be reversible.
C) extinction can be easily confirmed.
D) this species is at low risk of extinction.
E) extinction can occur for reasons other than human impacts.

Question 8

Australian pygmy bluetongue lizards were not seen for 33 years.They were thought to be extinct until one was discovered inside a snake in 1992.Prior to that time, only 19 individuals were known from anywhere in the world.The species inhabits a restricted geographic area and uses the burrows of spiders for refuge, the only lizard known to do so.Biologists did not observe bluetongue lizards because they did not look inside spider burrows.It has likely been difficult to determine the status of this lizard for all of the following reasons except that

A) it is small and extremely rare.
B) its life history and habitat were poorly known.
C) its interactions with other species were poorly known.
D) it is extremely reclusive.
E) it was not known or described before 1992.

Question 9

Which factor would scientists consider evidence that humans are causing the current mass extinction?

A) The extinction rate is lower than extinction rates from natural causes.
B) We can count the number of species currently going extinct.
C) Megafauna on all continents began to go extinct shortly after humans arrived.
D) Mass extinctions have occurred throughout history.
E) The extinctions are occurring only in regions densely populated by humans.

Question 10

The vaquita is a very small porpoise that lives in the Gulf of California.Its total population dropped from 60 to 30 total individuals between 2016 and 2017.It occurs with the totoaba fish, which is prized in Asia and illegally traded from Mexico to China.The vaquita is caught and drowned in fishing nets meant to catch the totoaba.The Clymene dolphin occurs in small groups of 60 to 80 individuals, with same sexes grouping together.It lives in the Atlantic Ocean and sometimes schools with common dolphins and spinner dolphins.The Clymene dolphin's world population is about 15,000.It is believed to be naturally rare.Which of these small cetaceans seems more likely to go extinct in the near future?

A) The vaquita, because it is specifically targeted by human fishers.
B) The Clymene dolphin, because it is naturally rare and therefore at risk.
C) The Clymene dolphin, because it has low reproduction due to separation of sexes.
D) The vaquita, because it is caught accidentally by human fishers.
E) The vaquita, because it is illegally traded.

Question 11

Determining the extinction of a species is difficult for a number of reasons, including lack of knowledge of their habitats, life cycles, and distributions.Given such difficulties, which of these animals would be most likely to be declared extinct?

A) Large grassland animal
B) Small underground animal
C) Bird living in a dense forest habitat
D) Insect living in a rainforest
E) Marine worm living on the ocean bottom

Question 12

Which initiative would not be included in modern conservation biology's efforts to preserve biodiversity?

A) Preserving the economic value gained from commercial fisheries
B) Protecting a species of butterfly for its intrinsic beauty
C) Protecting a woody shrub because of its medicinal applications
D) Protecting a sea otter because the community as a whole is more stable with that species present
E) Filling a marsh and bay to increase the size of a city

Question 13

Tropical rainforests are being destroyed in South America, Africa, and Southeast Asia.Every year, an area of rainforest the size of the country of Panama is destroyed.Much of this destruction is done by either clear cutting or burning, both of which leave the land completely barren.This loss of rainforest will likely have a negative impact on all of the following environmental factors except the

A) species diversity.
B) water cycle.
C) level of soil erosion.
D) local climate.
E) invasion of new species.

Question 14

Which situation would be considered an example of habitat degradation, as opposed to habitat loss or destruction?

A) Clearing land for agriculture
B) Clearing land to expand a city
C) Allowing land to be abandoned and badly eroded
D) Building a copper mine and leaving mine tailings in place
E) Building a hydroelectric dam and flooding the upstream area

Question 15

Vegetation protects the soil from erosion, and insect pollinators are necessary for the successful production of many food crops.These two functions depend on biodiversity and illustrate which reason for its importance?

A) Providing ecosystem goods and services
B) Providing psychological, including aesthetic, benefits
C) Maintaining humans' ethical values
D) Allowing scientists to study and understand ecological relationships
E) Giving the public an opportunity to learn about ecological relationships

Question 16

According to the International Union for Conservation of Nature (IUCN), the factor responsible for the most amphibian declines is

A) the fungal pathogen Batrachochytrium dendrobatidis (Bd).
B) habitat loss and degradation.
C) ultraviolet radiation.
D) climate change.
E) human-caused pollution.

Question 17

Extinctions, such as the extinction of the heath hen on Martha's Vineyard, Massachusetts, occur at the population or species level.But factors at other levels can be instrumental in causing an extinction.Which factor in the heath hens' extinction operated at the community level of diversity rather than the population level?

A) Fire
B) Hard winter
C) Influx of predators
D) Poultry disease
E) Demographic stochasticity

Question 18

Scientists varied the effective population size of a wildflower in a natural setting.After several generations, they found that populations with lower effective population sizes had lower rates of germination and survival because of inbreeding depression.This suggests that a low effective population size might eventually lead to

A) higher population growth.
B) extinction.
C) less inbreeding.
D) lower fluctuations in population size.
E) greater genetic diversity.

Question 19

Which statement is both correct and supports ecologists' view that amphibian species extinctions are increasing?

A) Nearly all amphibian declines are caused by habitat loss and habitat degradation.
B) Amphibian species are highly endangered in areas polluted or urbanized by humans, but not in undisturbed, natural areas.
C) Since 1980, 33 amphibian species are known to have gone extinct, and another 115 have not been seen.
D) Compared with amphibians, only birds and mammals have had more species go extinct since 1980.
E) Because of the fungal pathogen Batrachochytrium dendrobatidis (Bd), all amphibian species are expected to go extinct by 2100.

Question 20

Major causes of the global decrease in biodiversity include all of the following except

A) habitat loss and degradation.
B) overharvesting of species.
C) increased genetic diversity of populations.
D) species invasions and emerging diseases.
E) climate change.

Question 21

Blue whales, the world's largest animal, occur in all oceans except the Arctic.Before whaling, there were more than 250,000 blue whales.By 1967, when the species received worldwide protection, they were nearly all gone.Blue whale populations are recovering slowly compared with other whale species, such as humpbacks.This is most likely because

A) they are subjected to ocean challenges not felt by other whale species.
B) they reproduce more slowly than smaller species.
C) they are slower and easier for whalers to catch than smaller species.
D) restrictions on whaling have limited their ability to migrate.
E) whalers are now preying on the blue whales' food source.

Question 22

When the brown tree snake was introduced onto the island of Guam, its introduction resulted in the

A) extinction of the brown tree snake.
B) extinction of a number of native mammal species.
C) extinction of a number of native bird species.
D) spread of the tree snake onto neighboring islands.
E) seamless incorporation of the tree snake into the local ecosystem.

Question 23

Refer to the figure. The diagram shows the effects of large carnivore declines on other species in their food webs.Blue bars represent direct effects of carnivore declines, and red bars represent indirect effects.The data suggest that species such as deer increased when the carnivore left, and then caused the secondary decline of other species, such as hardwood trees.This means that the large carnivore served as a(n)

A) heterotroph, with a minor role in the ecosystem.
B) ecosystem engineer, which physically modifies the environment.
C) top predator, which maintains a trophic cascade, affecting lower trophic levels.
D) foundation species, which builds habitat for other species.
E) autotroph, which provides food for the rest of the food web.

Question 24

One way to determine whether a population is being overharvested is to determine when it is no longer sustainable-that is, when the population is being harvested faster than it can be replaced by its natural rate of reproduction.In the case of an exploited ocean fishery, an observer would first become aware that the fishery is being overharvested when fish biomass

A) increases but the fish caught are smaller.
B) drops to near zero and the fishery collapses.
C) remains the same every year, even though fish are being harvested.
D) declines every year, even though the harvest rate remains the same.
E) declines every year, but only if the harvest rate increases.

Question 25

Which is the least likely way in which an aquatic species might be accidentally introduced into U.S.waters?

A) Released in ballast water
B) In a contaminated cargo shipment
C) In infected fishing gear
D) Dumped with aquarium water
E) Attached to the hull of a ship

Question 26

An industry releases toxic chemicals into a river.An oil spill occurs off the Gulf Coast, polluting local beaches and fishery areas.A cruise boat in the Pacific releases its trash, most of it plastic, into the open ocean.All of these are examples of

A) edge effects.
B) habitat degradation.
C) overharvesting.
D) invasive pathogens.
E) climate change.

Question 27

An invasive species might have any of the following effects except

A) coexisting cooperatively with native species in the ecosystem.
B) introducing disease organisms into an ecosystem.
C) affecting an ecosystem function such as water availability or fire cycles.
D) hybridizing with wild populations, changing the ecosystem's genetic diversity.
E) causing a native species to become endangered.

Question 28

The flightless dodo bird lived on the island of Mauritius in the Indian Ocean.It was the largest animal on the island and had no predators.When Portuguese ships landed in 1505, the dodo was easy prey for sailors wanting a new food source.It was trapped on the island and unable to fly, so it could not get away.Sailors also introduced rats, pigs, and monkeys, which ate the dodos' eggs.The dodo was extinct by 1681.Which factors were important in its extinction?

A) Habitat loss and species invasions
B) Habitat loss and emerging diseases
C) Overharvesting and habitat loss
D) Overharvesting and species invasions
E) Overharvesting and emerging diseases

Question 29

Overharvesting would most likely result in extinction for a species that is

A) already critically endangered.
B) now classified as endangered or vulnerable.
C) not endangered and has a large population.
D) small, relatively unknown, and not prized for food.
E) used as food and can be easily replaced.

Question 30

For more than 200 years, sea otters were exploited for their beautiful pelts.When otter populations declined, populations of their main food source, sea urchins, exploded.Urchins then overharvested kelp, their primary food source, leaving areas barren of kelp and depriving many other species of habitat.This description suggests that the species in this ocean ecosystem that were harmed by sea otter overharvesting included

A) sea otters only.
B) sea otters and kelp only.
C) sea otters and sea urchins only.
D) kelp and species living in kelp only.
E) all organisms living in this particular ecosystem.

Question 31

Suppose a highly virulent virus is found in chickens and several wild birds in the United States.It is new to the United States but has been seen a few times in isolated cases in African birds.Scientists think it might have arrived in the United States in a shipment of parrots, at least one of which was infected.In the United States, this virus would represent a(n)

A) emerging endemic disease, because it recently emerged in the United States.
B) emerging endemic disease, because it emerged due to human-caused climate changes.
C) novel pathogen, because it was recently introduced into the United States.
D) novel pathogen, because it originated in Africa.
E) novel pathogen, because it is highly virulent.

Question 32

Refer to the figure. The map shows the movement of the fungal pathogen Batrachochytrium dendrobatidis, or Bd, through the countries of Costa Rica and Panama between 1987 and 2006.

According to the map, which is the best description of the movement of Bd during this time?

A) It moved steadily from Panama into Costa Rica.
B) It moved to increasingly higher elevations in both countries.
C) It showed an erratic pattern of movement.
D) It moved gradually from a starting point in Costa Rica.
E) It emerged from more and more regions.

Question 33

Edge effects are often damaging to the biodiversity of the original habitat because they

A) increase pollution in the original habitat.
B) increase the amount of living space in the original habitat.
C) result in habitats more similar to the new habitat than to the original one.
D) result in habitats more similar to the original habitat than to the new one.
E) decrease competition among species in the original habitat.

Question 34

A species can be considered invasive if it

A) is deliberately introduced.
B) is accidentally introduced.
C) is still present 10 years after introduction.
D) becomes established after only one introduction.
E) increases in abundance and has negative effects.

Question 35

In Gabon, West Africa, the Wotango tree is harvested for its medicinal bark.The bark's chemical cannot be synthesized in the lab; it must be obtained from the bark itself.Before 1985, a French pharmaceutical company owned the rights to the chemical and harvested the tree sustainably.In 1985, the company began granting harvesting licenses to local businesses.Now, harvesting is described as "out of control," because villagers need the income.What does this information suggest about the current and future status of the Wotango tree?

A) It is now being harvested sustainably, and its status should not change.
B) It is now being overharvested, but its population will soon stabilize.
C) It is now being overharvested and could rapidly go extinct.
D) It is now being underharvested, but overharvesting might become a problem in the future.
E) It is now being underharvested; taking more will stimulate the tree to grow faster.

Question 36

Bluefin tuna are ocean predators that feed on a variety of smaller fish, including herring, anchovies, sardines, bluefish, and mackerel.They maintain balance in these populations.Tuna are preyed on by some toothed whales and sharks, and their meat is prized by the Japanese as a source for sushi.Since World War II, human harvesting has depleted species numbers, leaving bluefins endangered.Conservationists say ecological extinction of bluefin tuna would have serious and unpredictable consequences.The most likely consequence is that loss of tuna would

A) interrupt a trophic cascade, triggering effects throughout the food web.
B) cause other species in the ecosystem to migrate to other areas in the ocean.
C) increase biodiversity by giving their prey a chance to increase their populations.
D) result in the rapid extinction of toothed whales and sharks, due to lack of food.
E) result in collapse of all food webs throughout the ocean.

Question 37

Biological control is the deliberate introduction of one species into an area to control an already invasive species.Mongooses were introduced to several Hawaiian islands in the 1880s to control rats in sugar cane fields.However, rats are nocturnal and mongooses are diurnal, so the two species never crossed paths.Instead, mongooses feed on nestlings and eggs of rare ground-nesting birds and endangered sea turtles.Mongooses usually avoid traps if prey is abundant.The U.S.Army is now trying a new mongoose trap used successfully in New Zealand.Based on this information, what can be said about the use of mongooses as a biological control method in this case?

A) It was completely successful.
B) It was partially successful.
C) It was unsuccessful and resulted in an invasive species.
D) It will be considered successful if the new traps work.
E) It will be considered successful if bird and turtle populations survive.

Question 38

A predatory invasive species enters an ecosystem that has an endangered species that serves as one possible type of prey.Which is the most likely outcome of the species interaction?

A) Both species will coexist with no negative effects on the ecosystem.
B) The invasive species will prey on and further endanger the native species.
C) The endangered species will prey on the invasive species.
D) The invasive species will prey on the endangered species but cause no ill effects.
E) The invasive species will prey on other species but not on the endangered species.

Question 39

Refer to the graph. Ocean fisheries began collapsing in the twentieth century because of increased demand and better technologies.According to the graph, what is the best conclusion that can be drawn about the status of these fisheries between 1950 and 2010?

A) The status improved gradually during these years.
B) The status declined gradually during these years.
C) The status improved more rapidly after about 1982.
D) The status declined more rapidly after about 1982.
E) The status varied so much that there is no clear trend.

Question 40

Many native pollinators in Hawaii were driven extinct by non-native species.Now, many beautiful native Hawaiian flowers are pollinated by the Japanese white-eye bird.At first, Japanese white-eyes coexisted with native birds, but recently their numbers have increased in old-growth forests, leaving native birds too little to eat and threatening their survival.Today, the Japanese white-eye could best be classified as

A) both introduced and invasive.
B) invasive, but not introduced.
C) introduced, but not invasive.
D) both pathogenic and invasive.
E) both pathogenic and introduced.

Question 41

The Arctic Ocean is experiencing some climate-related changes.Some waters have recently become ice-free because of rising temperatures.These waters are now too deep for some commercially important species such as Arctic cod.As ocean acidification increases, it will reduce the productivity of shelled organisms, including mollusks and some plankton.Also, stratification will likely become more intense.Warmer water will float on a layer of colder, denser, nutrient-rich water, preventing nutrients from reaching the surface.What will these changes most likely mean for Arctic fish populations?

A) Their productivity will be higher.
B) Their productivity will be lower.
C) Fish will be unable to survive and will move south.
D) As plankton and mollusks die out, new fisheries will open up.
E) Stratification will lead to different fisheries at different depths.

Question 42

A city planning agency wants to restore an abandoned industrial area to its original natural state, including restoration of its original biodiversity.Based on methods typically used in restoration ecology, they would likely carry out all the following activities except

A) planting the region with introduced (non-native) plants.
B) removing polluted soil and replacing it with clean soil.
C) revegetating the area with a variety of native plants.
D) reintroducing animal species that originally lived there.
E) contouring the land to restore the area's original water flow.

Question 43

A new fungal pathogen that affects certain oak trees is introduced into a forest.Why might this introduced pathogen be more damaging to forest species than an already present native pathogen?

A) Fungi do not typically live in forests, so no forest species will be adapted to it.
B) Forests cannot survive without oak trees, so the forest will die if the pathogen invades.
C) The forest's oak trees likely have defenses against native pathogens but not against the introduced pathogen.
D) Introduced pathogens are always more virulent than native pathogens and will overcome whatever species they encounter.
E) The introduced pathogen will be better adapted to the forest environment than any already present native pathogens.

Question 44

An invasive snail is accidentally introduced into a river.It carries a pathogen to which it is adapted; however, the pathogen is a generalist that can infect various other mollusk species in the river and downstream.What is the most likely effect the introduced pathogen will have on the mollusk diversity of the river?

A) It will remain in the invasive snail and will not affect the rest of the ecosystem.
B) It will decrease mollusk biodiversity as it spreads into local species that are not adapted.
C) It will enter other mollusks, but they will likely adapt readily to its presence.
D) It will try to enter other mollusk species but be unable to become established.
E) It will enter other mollusks but can be eradicated by removal of the invasive snail.

Question 45

Twenty-eight species of migratory birds on the East Coast are nesting earlier than they did 50 years ago.This piece of evidence is associated with which type of response of organisms to climate change?

A) Northward range shift
B) Altitudinal range shift
C) Change in timing of life cycle event
D) Food web disruption
E) Greater extinction risk

Question 46

A non-native mosquito species moves north into the United States, carrying with it a viral disease that affects humans.Epidemiologists, who track disease outbreaks, want to predict both the spread of the disease in humans and how serious its effect will be.Given that it is a new (introduced) virus, how will its effect likely compare with that of a viral disease spread by a native mosquito?

A) It should be no different, since both diseases are carried by mosquitoes.
B) It should cause a less serious disease, since it is not adapted to the area.
C) It should cause a less serious disease, since there are fewer of the new mosquitoes.
D) It should cause a more serious disease, since it will spread faster than a native virus.
E) It should cause a more serious disease, since no humans are adapted to it.

Question 47

Throughout the Northern Hemisphere, plant species are blooming several weeks earlier than they did 50 years ago.Also, their insect pollinators are emerging and reproducing earlier, so they require earlier-blooming flowers to provide pollen and nectar.These changes in timing are most likely caused by

A) rising temperatures due to climate change.
B) rapid genetic changes in the organisms' behavior.
C) loss of habitat, requiring more rapid life cycles.
D) increasing biodiversity, requiring more compressed life cycles.
E) lower temperatures due to climate change.

Question 48

Refer to the table. According to the table, do ocean organisms show the same general trends in response to climate change as are shown by terrestrial organisms?

A) No; they are not migrating in response to changing temperatures.
B) No; they show increased abundance rather than change in location.
C) It is impossible to say; terrestrial and ocean organisms cannot be compared.
D) Yes; like terrestrial organisms, they are migrating as the temperatures rise.
E) Yes; like terrestrial organisms, they are shifting upward in elevation.

Question 49

An area that restricts or prohibits habitat loss and degradation and that is designed to conserve and manage biodiversity and to replenish populations that might otherwise become extinct is known as a(n)

A) natural ecosystem.
B) biodiversity area.
C) coupled human-natural system.
D) suburb.
E) protected area.

Question 50

In recent years, deadly coral bleaching events have increased on reefs around the world.This increase is strongly correlated with rising reef temperatures.The worst bleaching events occur in years when an El Niño weather event occurs, causing even higher spikes in reef temperatures.Based on this evidence, one can conclude that El Niño weather events likely

A) are the cause of coral bleaching, rather than climate change.
B) cause greater coral bleaching than climate change.
C) amplify the effects of climate change by further increasing reef temperatures.
D) cause less coral bleaching than climate change does.
E) would not affect coral reefs unless climate change was also occurring.

Question 51

Refer to the table. According to the table, during the past several decades, plants have begun to show earlier flowering and leaf unfolding, butterflies have appeared earlier, and animals show earlier breeding and migration dates.How do these changes provide evidence for climate change?

A) They represent examples of species having unusual reactions to climate change.
B) They represent ways in which organisms are failing to adapt to the changing climate.
C) They correlate with temperature variations, which lead to random organism responses.
D) They correlate with temperature decline, which leads to spring beginning later.
E) They correlate with temperature rise, which leads to spring beginning earlier.

Question 52

A person living in a small town has a large backyard in which she cultivates a vegetable garden and several flower gardens.She plants flowering shrubs, hangs birdhouses, and sets up a birdbath.She provides habitat for butterflies and other pollinators, and for toads and other insect predators.The resulting backyard can best be described as a

A) protected area.
B) habitat corridor.
C) coupled human-natural system.
D) buffer zone.
E) fragmented habitat.

Question 53

A national park in Bolivia was designed with three distinct areas.Area A is a large central area designated "no extraction"; no resources of any kind can be removed from it.Area B is a large surrounding area populated by indigenous peoples and designated to allow them to continue to farm and hunt there.Outside both areas, area C is zoned for "extractive" uses (for example, livestock raising and a gas pipeline).What terms would best describe areas A and B, respectively?

A) A = Buffer zone, B = Protected area
B) A = Protected area, B = Buffer zone
C) A = Coupled human-natural system, B = Buffer zone
D) A = Habitat corridor, B = Protected area
E) A = Protected area, B = Habitat corridor

Question 54

Species are affected by rising temperatures, rising ocean acidity, and increased storms primarily as a result of

A) habitat loss and degradation.
B) behavioral changes in animals.
C) unknown causes.
D) human-caused climate change.
E) natural climate change.

Question 55

In the coming century, sea level rise will drown many coastal regions that now consist of wetlands.A modeling study of 12 wetland areas around San Francisco Bay predicts that, by 2100, 95 percent of these wetlands will be covered by an expected 3-4 feet of sea level rise.In addition to loss of flood protection and other ecosystem services, which ecological change might be expected to result from drowning wetlands?

A) Increased shorebird habitat and breeding sites
B) Loss of shorebird habitat and breeding sites
C) Decreased fish habitat
D) Increased wetland biodiversity
E) Increased reproductive rates in wetland species

Question 56

Habitat corridors, such as the overpasses across the Trans-Canada Highway, are most helpful in protecting biodiversity when they are used to connect

A) buffer zones to protected areas.
B) separate areas within a national park.
C) separate urban areas.
D) fragmented habitats such as separate reserves.
E) urban areas to industrial areas.

Question 57

Habitat corridors would be least effective in facilitating movement between natural areas for which of these species?

A) Wolves
B) Bobcats
C) Trees
D) Deer
E) Rabbits

Question 58

Emergence of a new endemic pathogen in an ecosystem (as opposed to a newly introduced pathogen) is most likely to occur by which method?

A) Climate change due to human activity
B) Escape of laboratory animals carrying the pathogen
C) Release of plants or plant seeds carrying the pathogen
D) Accidental introduction through global trade
E) Accidental introduction through international air travel

Question 59

Elevated atmospheric CO₂ concentration results in higher rates of plant photosynthesis.It also increases the plants' carbon-to-nitrogen ratio, causing a "nitrogen dilution" effect that decreases leaf protein levels and nutritional content.Herbivorous insects in elevated CO₂ conditions show a 22 percent decline in abundance, 17 percent increase in consumption rates, 4 percent increase in development time, 9 percent decrease in relative growth rate, and 5 percent decrease in pupa weight.These are average changes that vary by species and are most pronounced for chewing insects.These changes suggest that climate-induced increases in CO₂ levels will likely have

A) uniformly positive effects on terrestrial ecosystems.
B) uniformly negative effects on terrestrial ecosystems.
C) complex effects on ecosystems that vary by species and trophic level.
D) generally positive effects on plants and negative effects on animals.
E) generally positive effects on chewing insects and negative effects on others.

Question 60

Of these locations, the one most likely to be described as a human-natural system is a(n)

A) naturally occurring coastal wetland that provides flood control.
B) urban recreational area using all artificial décor, such as plastic palm trees.
C) wilderness area with no trails, roads, or other human structures.
D) organic farm that uses no artificial pesticides but depends on natural controls.
E) coastal area where ship canals are dredged to replace natural marshes.

Question 61

Ballast water from ships has been responsible for the intercontinental spread of a number of invasive species.One promising strategy proposed by conservationists to reduce this danger is to

A) pump out ballast waters on the open sea rather than in port.
B) use soil-based ballast rather than ballast water.
C) deoxygenate the ballast water before release.
D) chlorinate the ballast water before release.
E) retain the ballast water until the ship returns to its home port.

Question 62

The rate of extinctions that occurred normally throughout history, when mass extinction events were not occurring, is called the _______.

Question 63

In some parts of the Midwest, prairie restoration programs have required replacement of introduced agricultural grasses, such as bluegrasses, with the native prairie grasses that once thrived there.Prairie restoration proved difficult until scientists discovered that native prairie grasses were adapted to survive periodic wildfires, while introduced grasses were not.They changed their method to include prescribed burns.In this case, the restoration ecology project benefited from the use of which ecological concept?

A) Use of periodic disturbances to stimulate plant growth
B) Restoring biodiversity by reintroducing native animals
C) Use of ecosystem engineers to restore habitat
D) Use of vegetation to prevent erosion
E) Use of introduced species to improve habitat

Question 64

The use of CITES to protect an endangered species would be most appropriate under circumstances in which a species is threatened by

A) invasion of an exotic species.
B) destruction of its habitat.
C) illegal poaching and killing for a product.
D) environmental stress due to climate change.
E) pesticides in its environment.

Question 65

Michigan scientists are trying to save the endangered Kirtland's warbler, a small songbird that breeds only in even-aged stands of jack pine.They have replanted stands of jack pine and used prescribed burning to develop stands of the middle-aged trees the warblers prefer.Which ecological concept is being used to aid this restoration ecology project?

A) Use of periodic disturbances to stimulate plant germination
B) Restoring biodiversity by reintroducing native animals
C) Control of predators to make a safe environment for the warblers
D) Use of vegetation to prevent erosion
E) Restoration of original native habitat

Question 66

Human-caused changes such as habitat loss, overharvesting, and climate change often lead to lowered effective population sizes, which in turn lead to a loss of ecosystem _______.

Question 67

What major factor prevents the use of captive breeding programs as a solution for saving endangered species?

A) Breeding programs only work when a large population remains in the wild to teach captive-bred animals.
B) The number of endangered species exceeds the space and resources available to maintain them in the wild.
C) Breeding programs do not usually raise viable offspring.
D) Genetic diversity of species bred in captivity is far too high for them to survive in the wild.
E) Species bred in captivity become too attached to their keepers to be released into the wild.

Question 68

A species of bird is critically endangered, and its habitat is rapidly disappearing.A conservationist committed to preventing the extinction of this species would be most likely to undertake which type of program in the short term?

A) A tourism program to promote the bird species
B) A program to pass a national law to save both the bird and its habitat
C) An education program to teach people the importance of the bird species
D) A captive breeding program to buy time while the bird's habitat is restored
E) A program to protect the bird from invasive species

Question 69

When populations become smaller and lack genetic diversity, they are more likely to become _______.

Question 70

Up to 90 percent of saltwater fish caught for the aquarium trade are captured by dousing coral reefs with sodium cyanide.Many fish die, but those that receive only low doses are temporarily incapacitated, so they are easily captured.The coral reef, which cannot swim away, receives most of the cyanide.Many corals and other reef animals die, and the cyanide effects ripple through the food web.This information suggests that cyanide is hazardous to

A) the entire reef community.
B) mainly the targeted fish.
C) all reef fish.
D) all nonmotile reef dwellers.
E) all motile reef dwellers.

Question 71

Most wildlife trade is legal.It includes trade in both plants and animals; thus, exotic flowers, pets, wood used for furniture, and "wild" ingredients used in food and medicines are all included.Conservationists consider wildlife trade a problem when it is illegal and involves endangered species.This is most likely because endangered species

A) are more aggressive and more likely to kill poachers.
B) can be easily slipped past CITES officials at trade centers.
C) have low breeding populations, and illegal trade speeds up their extinction.
D) are more threatened by disease and invasive species once they are sold.
E) have a very low economic value, compared with species that are not endangered.

Question 72

Assume a potentially invasive species is about to be accidentally introduced into the United States via ship ballast water.The best way to control this species is to

A) prevent movement of the ship to its final destination.
B) use an eradication method as soon as individuals enter the water.
C) use an eradication method once the population is well established.
D) pass a law to ban accidental introduction of species.
E) prevent the introduction by treating ballast water before it is released.

Question 73

According to the categories set by the International Union for Conservation of Nature (IUCN), the species most highly threatened by extinction are classified as _______.

Question 74

One way ecologists try to estimate the effect of habitat loss on the rate of extinctions is by applying a concept from island biogeography known as the _______ relationship.

Question 75

Conservationists undertaking a restoration ecology project would most likely be seeking which outcome?

A) Establishing a new ecosystem that had never before existed in that location
B) Producing an ecosystem that functions better than the original system
C) Speeding up the natural process of ecosystem restoration
D) Introducing rapidly reproducing exotic species to repopulate the ecosystem
E) Producing a very stable, unchanging ecosystem

Question 76

A landowner wants to control an invasive plant species.He analyzes the spread of the plant and realizes that the plant infestation has three areas: a highly infested core area, a middle area or "advancing front" that has fewer plants but is expanding, and an outlier area that has the lowest plant density.The landowner decides to focus his first control efforts on the outlier area.What is his likely rationale for this choice?

A) It will prevent the need to control the inner areas.
B) It will kill off the only reproducing individuals.
C) It will be the hardest area to control because it was the earliest invaded.
D) It will prevent further outward spread of the invasive species.
E) It will kill off the slowest-growing individuals.

Question 77

Genetic drift, leading to inbreeding depression, combined with demographic stochasticity can threaten biodiversity because it results in a smaller _______.

Question 78

Which action is the best example of restoration ecology?

A) Converting an agricultural area into an industrial area
B) Returning an agricultural area back to its natural wetland state
C) Leaving an abandoned industrial site to return to nature on its own
D) Planting several new imported trees and shrubs on a suburban lawn
E) Adding windmills to an area of pastureland to provide wind energy

Question 79

Each country that participates in CITES issues a permit for the sale of all legal wildlife or plant species.Species listed by CITES are not permitted.At trade sites, merchandise is counted and checked to ensure its legality.In this way, the CITES agreement helps limit illegal trade in endangered species.What recent factor in elephant conservation has made enforcement of the CITES agreement less useful?

A) Elephants are now being killed so people can sell ivory to fund conservation efforts.
B) Legal or sanctioned ivory is now mixed with poached ivory and cannot be distinguished.
C) Elephants are no longer endangered, so CITES is no longer needed.
D) Elephants from all countries can now be legally sold, so CITES is no longer useful.
E) Elephant poaching is no longer a problem, so CITES is no longer needed.

Question 80

Since 1980, the world population of leatherback turtles has dropped by 63-77 percent.This decline has resulted from poaching for eggs and meat, destruction of nesting sites, accidental catches by fishermen, disorientation of nestlings due to artificial lighting from coastal developments, and more.This suggests that the decline in the leatherback turtle population is almost entirely due to _______, not natural, causes.