Chapter 26

Question 1

What was the approximate size of the human population in the year 2008?
A) 1.6 billion B) 2.6 billion C) 3.6 billion D) 6.6 billion E) 10 billion

Answer 1

D) 6.6 billion

Question 2

What percentage of the earth’s land area is currently used for crops or permanent pastures?
A) 1% B) 2% C) 5% D) 10% E) 35%

Answer 2

E) 35%

Question 3

Maintaining individual quality of life at a high level will require, above all, that humans exhibit a reproductive restraint that defies the entire history of evolution, during which “fitness” has been measured in terms of reproductive success rather than quality of life.
A) True B) False

Answer 3

A) True

Question 4

Which of the following have led to a reduction in birth rates and population growth in most regions of the world?
A) increased education (especially for women)
B) economic opportunity
C) urbanization
D) all of the above

Answer 4

D) all of the above

Question 5

About how many species of plants and animals worldwide have been described and given Latin names?
A) 150,000 B) 1.5 million C) 10 million D) 100 million

Answer 5

B) 1.5 million

Question 6

About how many species of plants and animals exist on the planet?
A) over 150,000 B) over 1.5 million C) over 10 million D) over 100 million

Answer 6

C) over 10 million

Question 7

Conservation of global biodiversity is best served by directing efforts toward areas of:
A) high diversity. B) high endemism. C) both A and B.

Answer 7

C) both A and B.

Question 8

Which of the following attributes are included in the definition of biodiversity hotspots, as recognized by Norman Myers of Oxford University?
A) high endemism D) A and B
B) high diversity E) A, B, and C
C) rapid habitat destruction

Answer 8

E) A, B, and C

Question 9

Biodiversity hotspots, not surprisingly, tend to have above-average densities of human populations combined with high human population growth rates.
A) True B) False

Answer 9

A) True

Question 10

Regions of high species diversity always support the highest numbers of endemic and threatened species.
A) True B) False

Answer 10

B) False

Question 11

Which of the following is a reason we should care about the extinction of species and work to conserve biological diversity?
A) moral responsibility
B) economic benefits
C) value of species as indicators of environmental quality
D) value of species in maintaining ecosystem function
E) all of the above

Answer 11

E) all of the above

Question 12

What fraction of medical prescriptions filled in the United States are drugs extracted directly from flowering plants?
A) none B) one-tenth C) one-quarter D) one-half E) all

Answer 12

C) one-quarter

Question 13

Assigning economic value to individual species raises awareness of the need to conserve biodiversity. Often, however, the assignment of economic value fails to address the issue of
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conserving biodiversity in a general sense. Why?
A) Assigning economic values to species is difficult in general.
B) We know nothing of the economic value of many potentially valuable species.
C) Assigning values to species of necessity favors some species over others.
D) All of the above are correct.

Answer 13

D) All of the above are correct

Question 14

In a national park in Zambia, the percentage of tuskless female elephants increased from 10% in 1969 to 38% in 1989. What was the direct cause of this increase?
A) illegal poaching by ivory hunters
B) fierce competition between male and female elephants for limited food resources
C) periodontal disease
D) The cause of this increase is unknown.

Answer 14

A) illegal poaching by ivory hunters

Question 15

When environmentalist Rachel Carson warned of a “silent spring,” she was referring specifically to:
A) the senseless slaughter of migratory birds by hunters.
B) the threat posed to birds by widespread application of pesticides.
C) the threat posed to insects by widespread application of pesticides.
D) the threat posed to amphibians by newly emerging diseases.
E) catastrophic drought caused by global climate change.

Answer 15

B) the threat posed to birds by widespread application of pesticides.

Question 16

The immediate threat posed by the pesticide DDT to predatory birds is:
A) mortality of adult birds.
B) male sterility.
C) overly thin eggshells and deaths of embryos.
D) inability of adults to fly.

Answer 16

C) overly thin eggshells and deaths of embryos.

Question 17

Researchers Tilman and Downing have demonstrated which of the following?
A) more stable biomass production during drought in high-diversity systems
B) more stable biomass production during winter in high-diversity systems
C) more stable biomass production under fertilization in high-diversity systems
D) more stable biomass production under pesticide application in high-diversity systems

Answer 17

A) more stable biomass production during drought in high-diversity systems

Question 18

What is a good estimate of the background rate of species extinction?
A) one species per day C) one species per millennium
B) one species per year D) one species per million years

Answer 18

B) one species per year

Question 19

What is a good estimate of the current rate of species extinction?
A) one species per day C) one species per millennium
B) one species per year D) one species per million years

Answer 19

A) one species per day

Question 20

Catastrophic destructions, like the one caused by the impact of a bolide with earth at the end of the Cretaceous, create opportunities for new types of biological associations. In the case of the end-Cretaceous catastrophe:
A) mammals and birds filled ecological vacancies left by dinosaurs.
B) ammonites filled ecological vacancies left by trilobites.
C) conifers filled ecological vacancies left by large primitive trees and ferns.
D) humans quickly became the dominant species on the planet.

Answer 20

A) mammals and birds filled ecological vacancies left by dinosaurs.

Question 21

About how often have catastrophic destructions of the magnitude of the end-Cretaceous bolide impact occurred?
A) at intervals of a billion years
B) at intervals of 10 to 100 million years
C) at intervals of 10 to 100 thousand years
D) only once

Answer 21

B) at intervals of 10 to 100 million years

Question 22

Which of the following kinds of extinction has been linked to collisions of bolides with earth?
A) background extinction B) mass extinction C) anthropogenic extinction

Answer 22

B) mass extinction

Question 23

Which of the following kinds of extinction is caused by humans?
A) background extinction B) mass extinction C) anthropogenic extinction

Answer 23

C) anthropogenic extinction

Question 24

Human activities have been identified as the causal factor in numerous documented extinctions. Which of the following specific causes has been identified in the majority of cases
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examined?
A) habitat reduction and modification C) introduction of exotic species
B) small population size D) overexploitation

Answer 24

A) habitat reduction and modification

Question 25

The largest U.S. national parks are of sufficient size to maintain populations of all mammal species originally found in these parks.
A) True B) False

Answer 25

B) False

Question 26

Habitat fragmentation poses severe threats to many species because of:
A) small size of local populations.
B) undesirable edge effects.
C) barriers to movement in response to changing conditions.
D) all of the above.

Answer 26

D) all of the above.

Question 27

A population that has experienced a genetic bottleneck and lost its genetic variability can never again attain substantial numbers.
A) True B) False

Answer 27

B) False

Question 28

Colonization by humans of Australia, the Americas, Madagascar, and New Zealand was soon followed by which of the following events?
A) widespread introduction of agricultural crops
B) extinction of a substantial portion of the vertebrate fauna
C) extinction of a substantial portion of the insect fauna
D) all of the above

Answer 28

B) extinction of a substantial portion of the vertebrate fauna

Question 29

One of the most surprising results from studies on biological introductions is that competition, rather than effects of predators and pathogens, is the main cause of decline in native species.
A) True B) False

Answer 29

B) False

Question 30

In which of the following settings have exotic species posed a larger threat to the native biota?
A) islands B) mainland areas C) A and B about equally

Answer 30

A) islands

Question 31

In the United States, purple loosestrife, Japanese and Amur honeysuckle, Australian Melaleuca, and Brazilian pepper are all:
A) native flowering plants nearly brought to extinction by consumption by exotic insects.
B) native flowering plants nearly brought to extinction by competition from exotic plants.
C) exotic flowering plants that have caused relatively few problems for native species.
D) exotic flowering plants that have caused significant problems for native species.

Answer 31

D) exotic flowering plants that have caused significant problems for native species.

Question 32

Why do aquatic systems seem particularly vulnerable to disruption by exotic consumers?
A) because higher temperatures result in faster population growth
B) because humans typically ignore problems in aquatic systems
C) because of the predominance of top-down control of community structure by consumers
D) because of the low productivity of aquatic ecosystems

Answer 32

C) because of the predominance of top-down control of community structure by consumers

Question 33

Which of the following species has become a pest after its introduction elsewhere from North America?
A) chestnut blight B) honeybee mite C) zebra mussel D) comb jelly

Answer 33

D) comb jelly

Question 34

Which of the following attributes makes species more vulnerable to anthropogenic extinction?
A) species attractive as human resources
B) species that have evolved in the absence of predation and disease
C) species with limited geographic range
D) species with restricted habitat distribution
E) all of the above

Answer 34

E) all of the above

Question 35

Which of the following is an appropriate goal for conservation?
A) protecting a variety of geographic areas
B) protecting endemic species
C) protecting habitats and areas of special biological interest
D) protecting large areas of intact habitat
E) all of the above

Answer 35

E) all of the above

Question 36

Which of the following incorporates demographic information about a particular population into a simulation model to predict the probability that it will avoid extinction within a given period, typically 100–1000 years?
A) metapopulation model
B) species-area relationship
C) population viability analysis
D) corridor analysis
E) all of the above

Answer 36

C) population viability analysis

Question 37

Which of the following principles associated with the theory of island biogeography can be helpful to individuals designing parks and reserves?
A) the Hardy-Weinberg law D) the Red Queen hypothesis
B) the species-area relationship E) none of the above
C) the polygyny threshold

Answer 37

B) the species-area relationship

Question 38

Which of the following species was rescued from the brink of extinction?
A) passenger pigeon D) Steller’s sea cow
B) California condor E) great auk
C) Nile perch

Answer 38

B) California condor

Question 39

Species whose distributions are limited to small areas are called __________.

Answer 39

endemic species

Question 40

The smallest population that can sustain itself in the face of environmental variation is called the __________.

Answer 40

minimum viable population

Question 41

Conservation of many species is difficult, especially when these species are not interesting or even perceptible to the general public. Such species often benefit, however, from living in association with other species that are highly valued by the public, such as giant pandas or cheetahs. The latter species are often referred to as __________.

Answer 41

flagship species

Question 42

The __________, which had disappeared from the eastern United States because of widespread pesticide use, is recovering there along with several other predatory birds rescued from the brink of extinction by a ban on use of DDT.

Answer 42

peregrine falcon

Question 43

The disappearance of 95% of species and numerous higher taxa at the end of the Paleozoic era is an example of a(n) __________ extinction.

Answer 43

mass

Question 44

Collisions of comets or asteroids (collectively referred to as __________) with earth are thought to have caused conditions leading to extinction.

Answer 44

bolides

Question 45

The process whereby populations have been greatly reduced through overfishing or overhunting has been referred to generally as __________.

Answer 45

overexploitation

Question 46

Conservation _________ have been identified based on high species diversity, high endemism, and imminent threats created by human activities.

Answer 46

hotspots

Question 47

popular conservation strategy is to connect isolated habitat patches with __________, thus ensuring migration routes for flora and fauna.

Answer 47

corridors

Question 48

Successful conservation of species depends on instilling values that acknowledge __________ as an integral part of the environment of humankind.

Answer 48

natural systems