Deck 38: Global Change

Question 1

Land and water transformations have many unintended consequences. One of the most serious is

A) the extinction of species.
B) continental drift.
C) the increasing concentrations of atmospheric ozone.
D) the reduction in global atmospheric carbon dioxide levels and the subsequent decline in worldwide NPP.

Answer 1

A

Question 2

Humans are particularly adept at water transformation; current estimates are that human activities have affected nearly _______ percent of the world's rivers

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

Answer 2

C

Question 3

The industrial production of fertilizers by humans

A) removes carbon dioxide from the atmosphere.
B) is causing a hole in the ozone layer.
C) has greatly increased the extent of human participation in the nitrogen cycle.
D) reduces the amount of acid rain.

Answer 3

C

Question 4

One of the major effects of an increase in atmospheric carbon dioxide is

A) an increase in average global temperature.
B) cooler average temperatures as carbon dioxide reflects sunlight back into space.
C) an acceleration of the depletion of ozone.
D) an increase in the pH of oceans and lakes

Question 5

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

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

Question 6

Converting atmospheric nitrogen into chemical forms that can be used biologically is called fixation. Which of the following organisms can fix nitrogen?

A) insects
B) oak trees
C) bacteria
D) fish

Question 7

Which of the following does not represent evidence for global warming?

A) The ten hottest years on record have occurred since 1990.
B) In Europe, bird and butterfly species have shifted their ranges northward.
C) The hole in the ozone layer over Antarctica has been growing in size.
D) Plants in northern latitudes have increased the length of their growing seasons.

Question 8

The organisms responsible for most of the conversion of atmospheric molecular nitrogen (N₂) to the nitrate or ammonium that can be used by most other organisms are

A) photosynthetic plants.
B) bacteria.
C) fungi.
D) mammals.

Question 9

Why do synthetic chemicals and metals tend to bioaccumulate so readily?

A) These substances are so rare in natural environments that living organisms have developed very efficient methods of collecting them.
B) Natural reservoirs are so large that when expressed as a concentration putting the same amount into an organism will always produce an elevated value.
C) Synthetic chemicals often have no nutritional value so they are simply stored in the body and passed on when an organism is eaten.
D) They are foreign to the metabolism of most organisms and the biochemical systems needed to remove them from the body do not exist.

Question 10

Although not directly toxic to living organisms chlorofluorocarbons (CFCs) have had unanticipated impacts on the atmosphere. The ecological impacts of CFCs will be

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

Question 11

The figure below shows the relative concentration of polychlorinated biphenyls (PCBs) in several members of a lake food web.
Although the lake trout and minnow are both fish, the lake trout is more contaminated. Why?

A) Lake trout are bigger so their bodies can store a greater quantity of PCBs.
B) PCBs dissolve poorly in water but readily in fat; lake trout have a higher percentage of body fat than minnows.
C) Lake trout are large and long-lived; when they respire the pass water over their gills allowing the PCBs in the lake to accumulate it their bodies.
D) Lake trout fed on minnows while minnows fed on crustaceans.

Question 12

In the past 45 years, people who fish are catching fewer large carnivorous fishes worldwide. Which of the following statements best explains the significance of this fact?

A) Humans will have to begin eating fish that are primary consumers, meaning we will gather less energy from each fish eaten than if we ate secondary consumers.
B) The large fish have been hunted to near extinction, and this will affect the populations of both their predators and their prey.
C) The large fish have moved to areas of the ocean where fishing is less intense.
D) Humans will have to become producers in order to gather the maximum amount of energy from marine food webs.

Question 13

Changes to the physical and biotic features of the earth are called land and water transformations. Which of the following is an example of a water transformation?

A) Clearing land along an urban-growth boundary to allow a city to expand.
B) Constructing a dam along a river so that expanding city may increase the availability of drinking water.
C) Clear-cutting a forest for the lumber needed to build the homes for an expanding city.
D) Clear-cutting a forest to make cropland to grow the food for an expanding city.

Question 14

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 15

When nitrogen is added to nitrogen-poor aquatic ecosystems, productivity _______ and the number of species _______.

A) increases; declines
B) increases; increases
C) declines; declines
D) declines; increases

Question 16

Ample evidence now exists to show that worldwide environmental changes are occurring; one example is

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

Question 17

The levels of carbon dioxide in the atmosphere

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

Question 18

Since 1950 the commercial fishing industry has applied continuously improving technologies for harvesting marine fish. What has been the effect of improved fishing efficiencies on ocean communities?

A) No substantial change has occurred; the oceans are simply too big for humans to have much of an impact.
B) Generally beneficial; as top predatory fish have been removed the biodiversity of many oceanic communities has actually expanded.
C) Quite disruptive; fishing has significantly altered the food webs of many ocean communities.
D) Generally beneficial; the selective removal of certain large carnivorous fish has led to an increase in the number of harvestable fish.

Question 19

Which of the following statements is not correct?

A) Land and water transformations are caused by humans.
B) Land and water transformations are global in scale.
C) Land and water transformations are currently occurring.
D) Land and water transformations have had little effect on Earth.

Question 20

Humans now utilize approximately 30-35 percent of the terrestrial net primary productivity (NPP). A result of this 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.

Question 21

Which of the following choices is a major difference between human-caused global change and that which occurs naturally?

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

Question 22

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 23

In comparison to past estimates extinction rates are currently high. Which of the following is the most plausible explanation?

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

Question 24

Carbon dioxide levels are increasing because

A) human agriculture has greatly increased the amount of carbon dioxide given off by plants during respiration.
B) humans have begun releasing 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 in the human population and domestic livestock has increased the amount of carbon dioxide being released through respiration.

Question 25

Which of the following represents the most significant anthropogenic modification to the nitrogen cycle?

A) industrial fixation of nitrogen to produce fertilizer
B) release of nitrogen dioxide as a waste emission from burning coal
C) production of nitrogen monoxide by car engines
D) nitrogen fixation by bacteria associated with agricultural crops such as peas

Question 26

Which of the following would cause the slowest global change?

A) continental drift
B) climate change
C) human activity
D) volcanic activity

Question 27

Which of the following is a source of naturally occurring carbon dioxide in the atmosphere?

A) cellular respiration by living organisms
B) the combustion of plant material ignited by lightning
C) volcanic eruptions
D) all of the above

Question 28

What best describes the relationship between cutting down forests and changes in atmospheric carbon dioxide levels?

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

Question 29

Why is the amount of nitrogen that cycles among organisms much smaller than the amount in the atmosphere?

A) Nitrogen is not needed by most of Earth's organisms.
B) Nitrogen gas in the atmosphere cannot be used directly by most organisms.
C) Human nitrogen fixation activities cause an increase in the amount of nitrogen gas in the atmosphere.
D) Nitrogen has a sedimentary nutrient cycle.

Question 30

Biodeisel fuel is produced from oils synthesized by and harvested from living plants. How does the use of biodeisel fuel compare to the use of fossil fuels with respect to the amount of carbon dioxide released to the atmosphere?

A) There is no difference; the combustion of the fuel produces carbon dioxide regardless of its source.
B) It is beneficial; converting plant material to biodeisel permanently traps carbon dioxide and prevents its entry to the atmosphere.
C) It is detrimental; since biodeisel produces lower mileage more must be burned, causing a proportional increase in carbon dioxide release.
D) It is beneficial; since living plants are the source of the biodeisel, burning it simply represents nutrient recycling.

Question 31

Global warming is likely to have much larger effects on some locations than others. Why are planners particularly concerned about California?

A) Grapes require cool spring weather; warming could impact the California grape harvest and plunge the state into an economic recession.
B) Warmer temperatures mean more ocean evaporation and cloud cover reducing the sunlight needed to drive the massive agricultural industry in California.
C) Warmer temperatures mean more ocean evaporation and rainfall; as this runoff reaches the coast it will reduce ocean salinities and impact coastal life.
D) The precipitation falling on the Sierra Nevada could be rain rather than snow; melting snow gradually releases critically needed water during the spring and summer.

Question 32

Intentionally supplementing nitrogen into a monoculture like a corn field has predictable and desirable results. Is the same true when added to a system as complex as a community?

A) Yes; both primary production and species diversity increase.
B) Yes; primary production decreases but species diversity increases.
C) No, both primary production and species diversity decrease.
D) No, primary production increases but species diversity decreases.

Question 33

The graph below illustrates the relationship between fishing effort and the catch of large predatory fish, like tuna, during the past 40 years.
What best explains the pattern illustrated in this graph?

A) Fish are adaptive and eventually learn to avoid hooks.
B) Anthropogenic chemical, thermal, and sound pollution has greatly reduced the carrying capacity for large predatory fish.
C) Large predatory fish are at the top of their food webs where biomagnification produces the greatest impact.
D) Highly efficient harvesting technologies remove these fish species at rates much greater than the rates of natural replacement.

Question 34

The figure below shows the predicted distribution of biomes following a 4ᵒ C increase in average global temperature.
What biome in North America, in addition to deserts, becomes more common and how can the change be explained?

A) Boreal forests expand because warmer temperatures reduce the extent of snow coverage and allow conifers to begin spring growth earlier.
B) Tundra expands because melted permafrost provides new habitat for cold-adapted grasses and herbs.
C) Topical forests expand because warmer temperatures expand tropical habitats, increase evaporation from the ocean surface, and provide the necessary rainfall.
D) Grasslands expand because warmer temperatures decrease average global rainfall, converting forest biomes to grasslands.

Question 35

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

A) The environment is much too big and the human population much too small in comparison to have any serious consequences.
B) Human societies may experience severe disruptions in the services ecosystems provide that human societies depend on.
C) Some short-term changes may be experienced, but the magnitude will likely be no greater than those that have occurred naturally.
D) Some beneficial and necessary reductions on population growth will occur.

Question 36

What is the main reason that humans acted quickly to ban substances that contribute to the hole in the ozone layer?

A) Industries using CFCs anticipated lawsuits and damage awards for ozone destruction unless changes were immediately made.
B) The hole in the ozone layer was allowing too many greenhouse gases to escape.
C) Ozone depletion and acid rain were shown to be directly linked.
D) Educational efforts were able to help people realize the personal impacts of ozone depletion, such as skin cancer, and motivated public sentiment to support a ban.

Question 37

The single most significant human caused contribution (about 75 percent) to the worldwide increase in atmospheric carbon dioxide is

A) acid rain and the subsequent chemical reactions that release carbon dioxide from the soil.
B) 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 38

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 39

When plants are initially exposed to elevated carbon dioxide levels most increase their rate of photosynthesis; how might plant communities be affected?

A) no changes other than increased NPP
B) competition increases for other resources such as sunlight or phosphorus with the eventual disappearance of some community members
C) community members decrease in size over time with the removal of the selection pressure for carbon dioxide acquisition
D) Since carbon dioxide is never a limiting factor like water, nitrogen, or phosphorus, increased levels typically have no significant effects.

Question 40

Atmospheric scientists anticipate a 3.5°C temperature rise in the next century; if so, what impacts will such change bring?

A) Some plant and animal species will migrate to cooler locations while others will become extinct.
B) There will be a positive impact on the world's agricultural systems as ocean evaporation and terrestrial rainfall increase.
C) Sea levels could rise high enough to improve the ease of navigability and shipping.
D) The polar ice caps will increase in size.

Question 41

Net primary productivity is typically limited by the amount of nitrogen and phosphorus available to producers, when these nutrients are increased NPP increases as well.

Question 42

When biologically useable nitrogen is increased in terrestrial communities, net primary productivity usually _______.

Question 43

As a group, the _______ gases allow light energy to pass through the atmosphere but absorb heat energy as it passes through the atmosphere to outer space.

Question 44

Nitrogen gas makes up approximately 20 percent of the air we breathe.

Question 45

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

Question 46

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

Question 47

The best hope for slowing the recent rapid ecological changes is to decrease the impact of _______ on Earth to a sustainable level.

Question 48

Human activities presently fix more nitrogen than all natural sources combined.

Question 49

Humans are changing the way many chemicals _______ through ecosystems.

Question 50

The conversion of N₂ to NH₄⁺ is called _______ _______.

Question 51

All global changes presently observed on Earth are due to human activity.

Question 52

The amount of nitrogen that cycles among organisms is _______ than the amount that is in the atmosphere.

Question 53

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

Question 54

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

Question 55

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 56

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

Question 57

The carbon that is increasing the levels of carbon dioxide in our atmosphere comes largely from fossil fuels.

Question 58

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 59

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

Question 60

Humans utilize approximately 15 percent of the world's total net primary production.

Question 61

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

Question 62

Even without the melting of polar ice, sea level is anticipated to rise because warm water expands.

Question 63

The atmospheric concentration of carbon dioxide is presently approaching values equal to those believed to have existed 420,000 years ago.

Question 64

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

Question 65

Most plants can be considered carbon sinks; their net effect on atmospheric carbon is to reduce its concentration.