d. Allowing scientists to study and understand ecological relationships

Chapter 57 1.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.P roviding ecosystem goods and services

• Providing psychological, including aesthetic, benefits

c.M aintaining humans’ ethical values

• Allowing scientists to study and understand ecological relationships

e.G iving the public an opportunity to learn about ecological relationships

ANSWER:

a 2.A group hoping to use natural biodiversity to provide psychological and aesthetic benefits to people would most likely carry out which project?a.P rotect a natural area for scientific study by selling it to a university

• Carefully create hiking trails and scenic overlooks in a natural area

c.C ut down parts of a natural forest for its lumber

• Reclaim a wetland to restore its flood control function

e.G ive speeches promoting the ethics of preserving endangered species

ANSWER:

b 3.Many people concerned with the importance of biodiversity to the human species emphasize its value to future generations. Which of these benefits is most directly associated with benefits to the future, as opposed to the present?a.M aintaining pollinator populations

• Preventing fishery areas from being polluted

c.M aintaining a natural study area for students and researchers

• Protecting species used by tribal or aboriginal peoples

e.P reserving rainforests as a source of undiscovered foods and medicines

ANSWER:

e

• Which initiative would

not be included in modern conservation biology’s efforts to preserve biodiversity?a.P reserving 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

ANSWER:

e

• Major causes of the global decrease in biodiversity include all

except a.h abitat loss and degradation.

• overharvesting of species.

c.i ncreased genetic diversity of populations... Powered by Cognero.Page 1 Test Bank for Life The Science of Biology (Digital Update) 12th Edition By David Hillis, Craig Heller, Sally Hacker, David Hall, Marta Laskowski, David Sadava (All Chapters 1-57 Arranged Reverse 57-1) 1 / 4

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• species invasions and emerging diseases.
• climate change.

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c 6.Biodiversity is declining because of habitat loss and degradation, overharvesting, species invasions, emerging diseases, and climate change. All of these have one major factor in common: they a.a re caused by humans.

• are caused by natural phenomena.

c.h appen quickly, with obvious results.

• cannot be reversed.

e.c ause changes on a single geographic scale.

ANSWER:

a 7.Several species of prairie plants go extinct from a drought brought on by climate change. The extinct plant species served several roles in the prairie ecosystem; they were food plants, were pollinated by various insects and birds, and produced root systems that held the soil in place. Given the loss of these plant species, which is least likely to be a consequence to the prairie ecosystem?a.D ecline of insect pollinators

• Increased erosion

c.R apid invasion of other plant species

• Overall decline in prairie diversity

e.O verall increase in prairie biomass

ANSWER:

c 8.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.h igher population growth.

• extinction.

c.l ess inbreeding.

• lower fluctuations in population size.

e.g reater genetic diversity.

ANSWER:

b 9.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... Powered by Cognero.Page 2 2 / 4

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Chapter 57 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:

a 10.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.F ire

• Hard winter

c.I nflux of predators

• Poultry disease

e.D emographic stochasticity

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c 11.A bout 90% of the original area of a freshwater marsh has been destroyed by agriculture and urban growth.Effective population sizes of the remaining frogs in the marsh have declined dramatically. In the future, marsh frogs are likely to see increases in all of the following factors except a.r eproductive rates.

• harmful alleles.

c.g enetic drift.

• inbreeding depression.

e.d emographic stochasticity.

ANSWER:

a 12.As a drought continues, subpopulations of a rat population gradually become smaller. In one subpopulation, the usual 1:1 ratio of males to females changes during one generation, so that there are three males for every single breeding female. This represents a change in a.e ffective population size.

• genetic diversity.

c.d emographic stochasticity.

• inbreeding depression.

e.g enetic drift.

ANSWER:

c 13.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.L arge grassland animal .. Powered by Cognero.Page 3 3 / 4

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• Small underground animal

c.B ird living in a dense forest habitat

• Insect living in a rainforest

e.M arine worm living on the ocean bottom

ANSWER:

a 14.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-billed in an Arkansas swamp.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 re-growing. 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.I t is probably extinct since no sightings have been made since 2005.

• It is probably extinct since the few sightings were likely of the last survivors.

c.I t is not extinct since it was recently seen and heard by competent ornithologists.

• Its extinction is not certain, because its swamp forest habitat makes it difficult

to track.e.I t will be considered extinct if recent photos and videos cannot be verified by experts.

ANSWER:

d 15.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.e xtinction cannot be easily confirmed.

• extinction can be reversible.

c.e xtinction can be easily confirmed.

• this species is at low risk of extinction.

e.e xtinction can occur for reasons other than human impacts.

ANSWER:

a 16.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.i t is small and extremely rare... Powered by Cognero.Page 4

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