Deck 25: Global Change

Question 1

Humans now use approximately 30-35 percent of the terrestrial net primary productivity (NPP).One result of this increased human control of NPP is that

A) human hunger has been virtually eliminated.
B) the number of species on Earth has increased.
C) humans are often in direct competition with other species for food and other natural resources.
D) we have learned how to manage Earth's resources so that all species have the resources they need to survive.

Answer 1

C

Question 2

Although they are not directly toxic to living organisms,chlorofluorocarbons (CFCs)have had unanticipated effects on Earth's atmosphere.The ecological impacts of CFCs will be

A) relatively benign, because even as secondary pollutants their toxicity remains low.
B) limited to the terrestrial ecosystem only.
C) limited to high-altitude communities where ultraviolet radiation is more intense.
D) uniformly serious, affecting almost all ecosystems and trophic levels.

Answer 2

D

Question 3

Ample evidence now shows that worldwide environmental changes are occurring.One example of these changes is the

A) increased net primary productivity observed within the world's aquatic ecosystems.
B) widespread increase of invasive species.
C) moderate decline in atmospheric carbon dioxide concentrations.
D) expansion of forested land as tree replanting efforts become more accepted.

Answer 3

B

Question 4

Which of the following statements about carbon dioxide levels in Earth's atmosphere is true?

A) They peaked around 1950 and have been slowly decreasing since then.
B) They are high now but are not higher than the highest estimated levels during the last 420,000 years.
C) They are estimated to be higher now than at any time in the past 420,000 years.
D) They began to decrease when the use of CFCs stopped.

Question 5

When most plants are initially exposed to elevated carbon dioxide levels,they will increase their rate of photosynthesis and grow more rapidly; however,some plants will drop their growth rates over time.A possible result of this phenomenon might be that plants with lower growth rates will

A) have an increased NPP.
B) be outcompeted by faster-growing species.
C) no longer play a role in the nitrogen cycle.
D) no longer require carbon.

Question 6

Which of the following statements about land and water transformations is NOT true?

A) They are caused by humans.
B) They are global in scale.
C) They are now occurring.
D) They have had little effect on the Earth.

Question 7

The single most significant human-caused contribution to the worldwide increase in atmospheric carbon dioxide levels is

A) acid rain and the subsequent chemical reactions that release carbon dioxide from the soil.
B) the use of nitrogen supplements that accelerate decompositional activity and recycle carbon before it can become sequestered in the soil.
C) the burning of fossil fuels and the subsequent emission of carbon dioxide.
D) deforestation and the subsequent decline in photosynthesis.

Question 8

An unusual aspect of the recent rise in atmospheric CO₂ levels is that

A) scientists have not been able to determine how it is happening.
B) CO₂ reacts so quickly with other compounds that this increase should not be happening.
C) it has happened relatively slowly.
D) it has happened relatively rapidly.

Question 9

Which of the following statements about POPs that have an atmospheric cycle is true?

A) They can have only localized effects.
B) They can be spread over large distances.
C) They cannot be bioaccumulated.
D) They cannot cause water transformations.

Question 10

Persistent organic pollutants (POPs)that interfere with hormone function are known as

A) greenhouse gases.
B) ozone depleters.
C) endocrine disrupters.
D) trophic contaminants.

Question 11

Changes to Earth's physical and biotic features are called land and water transformations.Which of the following human activities is an example of a water transformation?

A) clearing land along an urban growth boundary to enable a city to expand
B) constructing a dam along a river so that an expanding city may increase the availability of drinking water
C) clear-cutting a forest for the lumber needed to build houses for an expanding city
D) clear-cutting a forest to make cropland to grow food for an expanding city

Question 12

If all bacteria were suddenly unable to absorb mercury,biomagnification of methylmercury would most likely

A) stop.
B) continue.
C) continue, but only in the lower trophic levels.
D) continue, but only in the higher trophic levels.

Question 13

An increase in POP concentrations in higher trophic levels is the result of

A) biomagnification.
B) bioaccumulation.
C) bioacidification.
D) biodegradation.

Question 14

Which of the following statements about bioaccumulation and biomagnification is NOT true?

A) They both involve binding of chemicals to cells or tissues.
B) They both occur only through ingestion of chemicals.
C) They are both caused by humans altering natural nutrient cycles.
D) They both result in higher concentrations of a chemical in organisms than in the environment.

Question 15

Some chemicals and heavy metals bioaccumulate readily because they are

A) rare in the environments, so organisms collect them efficiently.
B) very concentrated in the abiotic environment.
C) stored in the body because they have nutritional value.
D) collected in the body more rapidly than they are removed.

Question 16

Skin cancer is caused by exposure to ultraviolet light.Which of the following chemicals is most likely to be associated with an increase in skin cancer rates?

A) chlorofluorocarbons
B) DDT
C) fossil fuels
D) methylmercury

Question 17

Humans are particularly adept at water transformation; scientists now estimate that human activities have affected nearly ________ percent of the world's rivers.

A) 10
B) 40
C) 70
D) 100

Question 18

Loss of biodiversity is an example of

A) global change.
B) global warming.
C) climate change.
D) net primary productivity.

Question 19

The release of chlorofluorocarbons (CFCs)into the atmosphere has caused a(n)

A) increase in the amount of usable nitrogen.
B) decrease in the amount of ultraviolet light reaching Earth.
C) increase in acid rainfall.
D) decrease in Earth's ozone layer.

Question 20

Carbon dioxide makes up approximately ________ percent of Earth's atmosphere.

A) 94
B) 44
C) 4
D) 0.04

Question 21

The addition of carbon dioxide to Earth's atmosphere also increases the amount of carbon dioxide dissolved in ocean water.This process has the effect of

A) cooling the ocean water by increasing the rate of evaporation.
B) warming the ocean water by decreasing the rate of evaporation.
C) increasing the acidity of ocean water because dissolved carbon dioxide makes the water more acidic.
D) decreasing the acidity of ocean water because dissolved carbon dioxide makes the water less acidic.

Question 22

Which of the following statements describes a major difference between human-caused global change and global change that occurs naturally?

A) Human-caused global change occurs more quickly, leaving organisms less time to adapt.
B) Human-caused global changes are smaller in scale than naturally caused changes.
C) Naturally caused global change occurs at only one place on Earth at a time.
D) Naturally caused global changes are limited to the terrestrial habitats where humans live.

Question 23

Atmospheric carbon dioxide levels are increasing because

A) human agriculture has greatly increased the amount of carbon dioxide given off by plants during respiration.
B) human activities have begun to release carbon that was formerly sequestered in fossil fuels into the atmosphere.
C) holes in the ozone layer have reduced the total amount of photosynthesis occurring in the biosphere.
D) the huge growth of the human population and the domestic livestock population has increased the amount of carbon dioxide being released through respiration.

Question 24

Which of the following factors does NOT contribute to the bush encroachment in Africa that is causing thorny plants to blind cheetahs?

A) The acidified soil selects for the growth of thorny plants.
B) Trees and shrubs are outcompeting the grasses of the grasslands.
C) Atmospheric carbon dioxide levels are rising.
D) Trees that grow faster are more likely to survive fires.

Question 25

Which of the following statements best describes the relationship between deforestation and changes in atmospheric carbon dioxide levels?

A) In the absence of forests, herbivore populations decline; without their respiration, less carbon dioxide is recycled into the atmosphere.
B) The carbon dioxide used by forest plants for cellular respiration would all be released into the atmosphere at once.
C) Trees naturally die and decompose, but when they are turned into lumber their carbon is prevented from recycling back to the atmosphere.
D) In the absence of forest plants, less carbon dioxide is removed from the atmosphere for use during photosynthesis.

Question 26

Atmospheric scientists anticipate a 1.1-6.4°C temperature increase by the end of the twenty-first century.What impacts would this change bring?

A) Some plant and animal species will migrate to cooler locations, whereas others will become extinct.
B) Increases in ocean evaporation and terrestrial rainfall will have a positive impact on the world's agricultural systems.
C) The frequency of severe weather will decrease.
D) The polar ice caps will increase in size.

Question 27

Which of the following phenomena is NOT evidence of global warming?

A) During the last decade from 2001-2010, the highest temperatures in history have been recorded.
B) In Europe, bird and butterfly species have shifted their ranges northward.
C) The frequency of severe weather and the length of storm seasons have decreased.
D) Plants in northern latitudes have increased the length of their growing seasons.

Question 28

Compared with past estimates,extinction rates are currently high.What is the most plausible explanation for this increase?

A) Natural fluctuations in climate are causing extinctions.
B) Continental drift is causing rapid changes in climate; these changes, in turn, cause extinctions.
C) Previous extinctions make survival of contemporary species more difficult.
D) Humans are affecting many aspects of the global environment.

Question 29

Which of the following cycles appears to make the greatest contribution to climate change?

A) the phosphorus cycle
B) the carbon cycle
C) the sulfur cycle
D) the nitrogen cycle

Question 30

Rainfall patterns around the world have changed because of

A) biomagnification.
B) ocean acidification.
C) global warming.
D) land transformation.

Question 31

Phytoplankton are ecologically important because they

A) are bioindicators of the amount of ice in the polar bear's ecosystem.
B) contribute to atmospheric oxygen through photosynthesis.
C) absorb acid to prevent ocean acidification.
D) are an important source of vitamins for polar bears.

Question 32

Suppose that a scientist discovers a method for removing 100 percent of the greenhouse gases from the Earth's atmosphere.Considering the information shown in the figure,would it be wise to use this technology?

A) Yes, because it would halt global warming.
B) Yes, because it would increase ocean acidification.
C) No, because too much infrared radiation would be absorbed by Earth's surface.
D) No, because too much heat would be lost back into space.

Question 33

Increased agricultural productivity in the northern latitudes is expected to be a consequence of global warming because

A) the increased temperatures will lead to a longer growing season.
B) cold-tolerant plants will adapt to become hardier.
C) soil acidification will occur in those areas.
D) agricultural productivity increases are predicted for all latitudes.

Question 34

Which of the following statements about the worst-case scenario results of climate change is true?

A) They cannot be averted and are inevitable.
B) They may be averted only if new technologies are discovered soon enough.
C) They can be averted only if the human population decreases by half.
D) They can be averted with the use of currently available technologies.

Question 35

Having a sustainable impact on the Earth and our biosphere means that we must

A) produce more fertilizers to feed a growing population.
B) take advantage of global warming by growing more crops in areas that were previously unavailable for agriculture.
C) find ways to recycle carbon dioxide more rapidly.
D) create better balances between our consumption of resources and the rates at which they can be replenished.

Question 36

Some northern species have shifted their habitats farther north in response to global warming.However,it is difficult for Arctic species to shift their habitats in response to rising temperatures because

A) they are not as mobile as other species.
B) they have broader habitat tolerances.
C) they are more susceptible to UV radiation.
D) their habitat is shrinking.

Question 37

What will happen in the future if humans continue to impact natural systems at the same rates as today?

A) There will not be any serious consequences, because the environment is much too big and the human population is much too small in comparison.
B) Human societies that depend on the services ecosystems provide may experience severe disruptions in those services.
C) The environment may experience some short-term changes, but their magnitude will likely be no greater than those that have occurred naturally.
D) Some beneficial and necessary reductions in population growth will occur.

Question 38

What characteristics would we expect to find in species that will most likely prosper as projected climate change occurs?

A) organisms with narrow tolerances that can live in specialized environments
B) organisms with broad tolerances that can live in a variety of habitats
C) organisms that live in very stable environments
D) organisms that can live only if they form mutualistic relationships with other organisms

Question 39

The example of cheetahs blinded by thorny plants indicates that the effects of chemical cycle disruption

A) produce a chain reaction of results that cannot always be predicted.
B) can all be predicted by ecologists who are experts in their field.
C) are very limited and probably won't affect humans.
D) will not be observed for decades.

Question 40

Pikas,shown in the photograph,are adapted to mountainous environments.How are species such as pikas changing their habitats in response to global warming?

A) They are moving northward toward the Arctic.
B) They are moving their ranges up the mountains to cooler habitats.
C) They are inhabiting areas that are closer to cool mountain lakes.
D) They are inhabiting areas that are adjacent to mountain glaciers.

Question 41

Humans have had a lasting impact on the physical appearance of Earth.

Question 42

Global warming is causing the frequency of storms and severe weather to increase because the rising temperatures also increase ________ energy.

Question 43

The physical and biotic changes humans make to the land surface of Earth are collectively known as land ________.

Question 44

Increased carbon dioxide levels in the atmosphere cause the pH levels of oceans to ________.

Question 45

The cutting and burning of forests has led to an increase in global ________ levels.

Question 46

Using more "green" building materials,recycling more waste,using bicycles more,and reducing the use of fossil fuels are examples of ways that we can work toward ________.

Question 47

Humans are changing the way many chemicals ________ through ecosystems.

Question 48

Wetlands are one of the few habitats to have escaped human-caused destruction; the worldwide distribution of wetlands has remained relatively stable for the past 200 years.

Question 49

As a result of climate change,areas that are far from water may become drier because global warming causes evaporation rates to ________.

Question 50

Because wetlands have relatively little economic value,the percentage of the United States that is covered by wetlands has been relatively stable during the past 200 years.

Question 51

All global changes that scientists are now observing on Earth are the result of human activity.

Question 52

As a result of climate change,rates of infectious disease caused by dengue fever virus and West Nile virus may increase because of the habitat shifts of ________.

Question 53

The best hope for slowing Earth's rapid ecological changes is to decrease the ________ impact on the biosphere to a sustainable level.

Question 54

About 50 percent of the human population lives near ________ ecosystems.

Question 55

Long-lived synthetic organic molecules that bioaccumulate in organisms are referred to as ________.

Question 56

Gases that enable light energy to pass through the atmosphere into outer space but that trap heat energy on Earth are known as ________ gases.

Question 57

Scientists predict that current increases in atmospheric carbon dioxide concentrations will cause temperatures on Earth to rise,a phenomenon known as ________.

Question 58

Bisphenol A,a chemical found in plastic water bottles,has been shown to increase the risk of diabetes and reproductive problems,among other disorders.Bisphenol A is a(n)________.

Question 59

Humans use approximately 30 percent of the world's total net primary productivity (NPP).

Question 60

Plants remove carbon dioxide from the atmosphere through the process of ________.

Question 61

Scientists can predict all the effects that increased atmospheric carbon dioxide will have on the biosphere.

Question 62

Global levels of atmospheric carbon dioxide have risen dramatically during the past 200 years.

Question 63

Climate change has not started and it can be prevented with timely action.

Question 64

A human-made chemical bioaccumulates if it is easily absorbed by an organism and then quickly broken down and excreted by the organism.

Question 65

The highest concentrations of environmental pollutants are typically found in the predators at the top of the food chain.

Question 66

Only natural nutrients cycle through ecosystems; synthetic chemicals do not cycle through ecosystems.

Question 67

Ample evidence now demonstrates that human activities are strongly associated with global warming.

Question 68

The atmospheric concentration of carbon dioxide is now approaching levels equal to those estimated to have existed 420,000 years ago.

Question 69

Even without the melting of polar ice,global warming is causing sea levels to rise because warm water expands.

Question 70

The carbon that is increasing the levels of carbon dioxide in Earth's atmosphere primarily comes from the burning of fossil fuels.

Question 71

A shift in the geographic range of a species due to global changes has caused the blindness that is now threatening cheetahs in Africa.

Question 72

The effects of global warming have already been detected in both aquatic and terrestrial ecosystems.

Question 73

The only way POPs affect the biosphere is through bioaccumulation.