Ecology Test 4

Front 1

1. Which of the following ecologists coined the term ecosystem, recognizing that the biota, plus their physical environment, constitute a fundamental level of ecological organization?

Back 1

A.G. Tansley

Front 2

2. The "food web" concept focuses on feeding relationships as the links connecting the organisms of “bioan” ecological system into a single functional entity. Which of the following twentieth-century ecologists was one of the earliest to promote this concept?

Back 2

Charles Elton

Front 3

3. Are the following items part of ecosystem structure or function?
Soil
Nutrient Cycle
Respiration
Species Composition

Back 3

Structure, Function, Function, Structure

Front 4

4. The _________ law of thermodynamics can explain why, in a terrestrial ecosystem, there is more energy stored __________.

Back 4

second … in herbivores rather than carnivores

Front 5

5. The _________ law of thermodynamics can explain why, in a terrestrial ecosystem, there is less energy stored __________.

Back 5

second... in carnivores rather than in herbivores

Front 6

6. In any ecosystem, the higher the light intensity, the greater the rate of net primary production.

Back 6

False

Front 7

7. One of the following broad ecosystem types achieves a net primary productivity that can exceed that of tropical forest. Which is it?

Back 7

swamp and marsh

Front 8

8. Which of the following broad ecosystem types has the least primary productivity?

Back 8

Tundra and alpine

Front 9

9. Using modern techniques for measuring gas exchange (based on absorption of infrared light), it is possible to determine within seconds the primary productivity of a small terrestrial plant or even one of its leaves. Which of the following compounds would be monitored by such a measurement?

Back 9

carbon dioxide

Front 10

10. The energy ingested by an animal minus that energy excreted (in feces, etc.) is known as

Back 10

assimilated energy

Front 11

11. Given what you know about transfer of energy from one trophic level to the next, what can you conclude about the potential food-chain length in natural ecosystems?

Back 11

there is an upper limit to the number of trophic levels in a food chain, probably around 4–5.

Front 12

12. The Odum energy diagram symbol with a bullet shape represents:

Back 12

producer

Front 13

13. The Odum energy diagram symbol with a "bird house" shape represents:

Back 13

storage

Front 14

14. The Odum energy diagram symbol with a hexagonal shape represents _____ and anteaters are _____.

Back 14

Consumers, Insectivores

Front 15

15. The average residence time of water in liquid form on the earth's surface is about _______ years

Back 15

2800 years

Front 16

16. Most of carbon on Earth are in __________.

Back 16

sedimentary rocks

Front 17

17. The "photosynthetic efficiency" of most ecosystems, that is, the ratio of net primary production to the solar energy available to the autotrophs is about:

Back 17

1-2%

Front 18

18. Which of the following has been monitored to determine primary productivity in aquatic plants, employing pairs of sealed bottles (“light” and “dark”)?

Back 18

Oxygen

Front 19

19. Energy used in _________ is NOT part of the “respired energy” of an animal.

Back 19

Reproduction

Front 20

20. If we take a "ballpark estimate” of 10% for ecological efficiencies of herbivores and carnivores, what percentage of the energy content of net primary production would we expect to find in production at the third (carnivore) trophic level?

Back 20

1%

Front 21

21. Which of the following is NOT a heterotroph?

Back 21

Algae

Front 22

22. The San Antonio area is dependent on water from _______.

Back 22

The Edwards Aquifer that is rapidly recharged

Front 23

23. Match the 3 processes of carbon cycle with their time scales:
*Photosynthesis and respiration which exchange CO2
*Exchange of CO2 between atmosphere and oceans, lakes and rivers
*Dissolution of C in water vs. precipitation (deposition) of carbonate sediments (limestone and dolomite sedimentary rock)

Back 23

Short time scale, intermediate time scale, long time scale

Front 24

24. Which of the following is NOT considered “ecosystem structure”?

Back 24

Photosynthesis

Front 25

25. The photosynthetic efficiency of an ecosystem can be limited by _____________.

Back 25

Temperature, moisture, and nutrients

Front 26

26. Which of the following plant consumers would you expect to exhibit the highest assimilation efficiency?

Back 26

herbivores feeding on seeds and young vegetation

Front 27

27. The ecological efficiency states that about _____ of the energy captured at one trophic level is passed on to the next level

Back 27

5-20%

Front 28

28. The Odum energy diagram symbol in the shape of a circle (from outside of a system) represents:

Back 28

Forcing function

Front 29

29. Ground finches specialized in eating seeds are called

Back 29

Granivores

Front 30

30. The global assimilation rate of carbon by photosynthesis is approximately 85 gigatons per year, balanced by an equivalent rate of dissimilation by respiration. Given a global organic carbon pool (excluding fossil carbon) of 2650 gigatons, what is the average residence time of carbon in this pool?

Back 30

31 years (because 2650/85=31.18)

Front 31

31. The concept of the ecosystem as an energy-transforming machine obeying thermodynamic principles was not widely accepted in the early part of the twentieth century. It was not until the 1940s that the work of a young aquatic ecologist, __________, brought widespread attention to this concept.

Back 31

Raymond Lindeman

Front 32

32. The energy remaining in autotrophs after respiration (GPP-R) is:

Back 32

Net Primary Production

Front 33

33. The ________ is the proportion of the gross energy intake that is assimilated.

Back 33

Assimilation efficiency

Front 34

34. Pitcherplant, a plant that can trap and consume insects, is:

Back 34

mixotroph

Front 35

35. The flow of energy from plants to herbivores to carnivores represents:

Back 35

grazing food chain

Front 36

36. What percentage of solar energy striking the earth provides the energy required to drive theglobal water cycle? [ALSO A CLICKER QUESTION]

Back 36

25%

Front 37

37. What percent of the Earth's total water are fresh water?

Back 37

3%

Front 38

38. The assimilation efficiency (assimilation / ingestion):

Back 38

Is lower in grazers than in carnivores

Front 39

39. The open ocean is sometimes referred to as a "biological desert" because of its very low primary production. What is the most important factor limiting primary production in open ocean?

Back 39

low availability of nutrients

Front 40

40. Only one of the following lists correctly ranks four terrestrial ecosystems from most to least productive. Which is it?

Back 40

Tropical forest, temperate forest, savanna, tundra

Front 41

41. How can humans increase their food supply?

Back 41

By eating lower on the food chain

Front 42

42. Which of the following is NOT an autotroph?

Back 42

Fungi

Front 43

43. The large-scale agricultural production on the high plains of the Texas Panhandle is dependent on water from _______.

Back 43

The Ogallala Aquifer that is slowly recharged

Front 44

44. The flow of energy from dead particulate organic matter to detritivores to predators represents:

Back 44

detritus Food Chain

Front 45

45. Specialized leaf eaters are:

Back 45

Folivors

Front 46

46. Spiders are:

Back 46

Carnivores

Front 47

47. The ratio of energy channeled into net production (growth and reproduction) to the energy assimilated is the organism's net production efficiency. Which of the following would you expect to have the highest net production efficiency?

Back 47

Sedentary cold blooded animals

Front 48

48. Plants, algae, and some bacteria capture the energy of sunlight and store it in chemical form. We refer to these organisms collectively as_______.

Back 48

Primary producers

Front 49

49. The open ocean is sometimes referred to as a “biological desert” because of its very low primary production. What is the most important factor limiting primary production in Open Ocean?

Back 49

Low availability of nutrients

Front 50

50. The ecological efficiency [or food chain efficiency] refers to the percentage of energy transferred from one trophic level to the next. Which of the following is a typical range of ecological efficiencies?

Back 50

5-20%

Front 51

51. Where did most of this mass come from [tree stump]?

Back 51

CO2

Front 52

52. The more the precipitation, the greater the rate of net primary production

Back 52

True (until a certain point when precipitation causes flooding and there is no more production)

Front 53

53. Characterize the pre-industrial atmospheric carbon dioxide concentration in the context of the earth’s geologic history.

Back 53

It was probably at the lowest level in the earth’s geologic history

Front 54

54. What percentage of solar energy striking the earth provides the energy required to drive the global weather cycle?

Back 54

25%

Front 55

55. Which of the following abiotic processes can result in the transformation of atmospheric nitrogen gas [N2] to ammonia [NH3] available to plants and microorganisms?

Back 55

Lightning

Front 56

56. Which of the following land use type export more phosphorus to the aquatic systems such as streams and lakes?

Back 56

Urban

Front 57

57. Which of the following region is a more important source of N to the Gulf?

Back 57

Ohio

Front 58

58. A stream flowing through or under a glacier can leave deposits of soil and rock in its path. After the retreat of the glacier, these deposits appear as a long, winding hill in the landscape, creating a unique microhabitat, What is the name applied to this structure?

Back 58

Esker

Front 59

59. Using this system, a researcher can bring together diverse sets of geographic information to quantify characteristics of the landscape mosaic and to determine how organism are affected by landscape characteristics

Back 59

GIS

Front 60

60. The degree of resolution at which an organism experiences variation in the landscape is referred to as:

Back 60

Grain

Front 61

61. Which of the following ecologists was the first to apply thermodynamic principles to the study of ecological systems?

Back 61

Alfred J. Lotka

Front 62

62. Which of the following statement is TRUE regarding landscape structure and landscape process?

Back 62

Landscape structure affects landscape process, and vice versa.

Front 63

63. If we consider the areas within 100 m of forest to cropland edge as the edge habitat, which of the following patch has the HIGHEST proportion of interior habitat?

Back 63

A square patch 100 ha in size (1000 m by 1000 m)

Front 64

64. As the tigerbush landscape became fragmented from 1960 to 1992, the average vegetation patch size_______ and the average vegetation patch shape index______

Back 64

Decreased...decreased

Front 65

65. Listed below are five consequences of habitat fragmentation. Which of these is directly responsible for an overall decrease in species richness?

Back 65

Total amount of habitat decreases

Front 66

66. Listed below are five consequences of habitat fragmentation. Which of these favors the brown-headed cowbird?

Back 66

Amount of edge habitat increases

Front 67

67. Both density of tick nymphs and percentage infected with the bacterial agent of Lyme disease were highest in the smallest forest fragments. What was the principal cause of the relationships observed?

Back 67

Increased abundance of white-footed mice in small forest patches

Front 68

68. About how many species of plants and animals worldwide have been described and given Latin names?

Back 68

1.5 Million

Front 69

69. Conservation of global is best served by directing efforts toward areas of:

Back 69

High diversity and high endemism

Front 70

70. Which of the following kinds of extinction has been linked to collisions of bolides with earth?

Back 70

Mass extinction

Front 71

71. Which is NOT a reason that limits food chains to 4-5 trophic levels?

Back 71

There is not enough physical space for predator species of higher trophic levels

Front 72

72. In the process of ________, one molecule of C6H12O6 is broken down in the presence of O2 to release CO2, H2O and 38 molecules of ATP

Back 72

aerobic respiration

Front 73

73. The energy ingested by an animal minus that energy excreted (in feces, etc.) is known as

Back 73

assimilated energy

Front 74

74. The net production efficiency (production / assimilation) for warm-blooded animals ________ that for cold-blooded animals:

Back 74

Lower than [homeotherms: 1-3%, poikilotherms: 20-50%]

Front 75

75. Regions of high species diversity always support the highest numbers of endemic and threatened species

Back 75

False

Front 76

76. What fraction of medical prescriptions filled in the United States are drugs extracted directly from flowering plants?

Back 76

one-quarter

Front 77

77. When environmentalist Rachel Carson warned of a ‘silent spring,’ she was referring specifically to?

Back 77

The threat posed to birds by widespread application of pesticides

Front 78

78. Introduction of a single exotic predator is most likely to disrupt ecosystem function if the introduced species is a _______ predator

Back 78

Keystone

Front 79

79. Application of fertilizers to aquatic ecosystems stimulates primary production just as it does in agricultural ecosystems. In aquatic ecosystems, the enhanced production can eventually lead to:

Back 79

Anoxic conditions

Front 80

80. Which of the following ecosystems services is considered indirect and dependent more on maintenance of intact ecosystems and less on availability of particular species?

Back 80

Production of clean air and water

Front 81

81. Solar energy that reaches the earth's surface may be absorbed and re-radiated by an object. The outgoing wave lengths are _________ the incoming wave lengths.

Back 81

Longer than

Front 82

82. What kinds of organism are capable of carrying out ammonification?

Back 82

All organisms

Front 83

83. The Phosphorus cycle is not of particular interest to ecologists because phosphorus is not an essential element.

Back 83

False

Front 84

84. Which of the following statement is TRUE regarding landscape structure and landscape process?

Back 84

Landscape structure affects landscape process, and vice versa.

Front 85

85. If patch A and patch B are of the same size but patch A has a GREATER patch shape index value than patch B, then patch A has _____ edge habitat than patch B.

Back 85

More

Front 86

86. The World Land Trust and Wildlife Trust of India are collaborating to protect important habitat corridors to ensure the long-term persistence of which of the following charismatic animals?

Back 86

Asian elephant

Front 87

87. If we have just clearcut 70% of a forested area with clear cut areas well distributed and connected with logging roads, what would be the matrix of the landscape?

Back 87

clearcut area

Front 88

88. ___________ in the 1960s-1980s is likely a major cause of the fragmentation of the tiger bush landscape in Niger.

Back 88

Significant human population growth and associated fuel wood consumption.

Front 89

89. Habitat fragmentation results in increased patch isolation, smaller patch size, and higher patch numbers, all of which have uniformly negative effects on species richness.

Back 89

False

Front 90

90. Images acquired from airplanes and satellites can be used to identify features on the earth’s surface and their locations in landscapes. Which wavelengths of reflected radiation make it easy to identify areas of vegetation, which typically stand out as bright red in the images produced?

Back 90

visible or near infrared

Front 91

91. The landscape scale that an animal experiences in the course of its movements is referred to as:

Back 91

Extent

Front 92

92. Which of the following abiotic processes can result in the transformation of atmospheric nitrogen gas (N2) to ammonia (NH3) available to plants and microorganisms?

Back 92

Lightning

Front 93

93. The cycling of elements within an ecosystems is a result of:

Back 93

All of the above (physical, biological, and chemical processes)

Front 94

94. Most of phosphorus on earth are in?

Back 94

Sedimentary Rocks

Front 95

95. Most of the Nitrogen on earth is in the?

Back 95

Atmosphere

Front 96

96. In an open grassland landscape, a wooded stream corridor could function:

Back 96

All of the above (as a conduit to forest/woodland animals, as a barrier to grassland animals, and as a barrier or filter to runoff and erosion)

Front 97

97. For species with good dispersal capabilities (birds and flying insects, for example), one of the following may suffice to provide connectivity between patches of suitable habitat, without the need for a continuously connected corridor.

Back 97

Stepping stones

Front 98

98. Fragmentation of the tiger bush landscape in Niger

Back 98

Decreased landscape’s ability to retain water

Front 99

99. Listed below are five consequences of habitat fragmentation. Which of these favors the brown-headed cowbird?

Back 99

Amount of edge habitat increases

Front 100

100. Using this system, a receiver picks up signals from orbiting satellites and processes these signals to determine latitude, longitude, and elevation of any location on earth.

Back 100

GPS

Front 101

101. Is biological nitrogen fixation _________ process?

Back 101

an assimilatory

Front 102

102. If atmospheric carbon dioxide (CO2) concentration were decreased, one might expect:

Back 102

the earth to get colder

Front 103

103. If atmospheric carbon dioxide (CO2) concentration were increased, one might expect:

Back 103

the earth to get warmer

Front 104

104. Which of the following region is a more important source of N to the Gulf?

Back 104

Ohio

Front 105

105. What is the matrix of a post oak savanna landscape (~10 km2) that consists of grass areas (60%), wooded areas (30%), crop fields (7%), and water (3%)?

Back 105

Grass areas

Front 106

106. What is the matrix of a post oak savanna parkland landscape (~10 km2) that consists of grass areas (35%), wooded areas (50%), crop fields (10%), and water (5%)?

Back 106

wooded areas

Front 107

107. In the study of the effects of patch size on animal movement at the Miami University in Oxford, Ohio, _______.

Back 107

rodents move shorter distance and more frequent in larger habitat patches.

Front 108

108. We saw the relationships of the density of nymphs of the black-legged tick and the percentage of tick nymphs infected with Borrelia burdorferi (the bacterial agent of Lyme disease) to area of forest fragments. Both density of tick nymphs and percentage infected were highest in the smallest forest fragments. What was the principal cause of the relationships observed? [ALSO A CLICKER QUESTION]

Back 108

increased abundance in small forest patches of white-footed mice

Front 109

109. Aside from that produced by biological nitrogen fixation, biologically available nitrogen is abundantly available in various rocks and minerals, which can be mined for fertilizer.

Back 109

False

Front 110

110. How do free-living cyanobacteria obtain the energy necessary to reduce atmospheric nitrogen gas (N2) to ammonia (NH3)?

Back 110

Photosynthesis

Front 111

111. Earl Werner and colleagues found that turnover (percentage change in species composition per year) of larval amphibians in wetlands in southeastern Michigan was directly related to which property of these wetlands?

Back 111

Connectivity to other wetlands

Front 112

112. Ancient farming practices, wildfires, ecosystem engineers, and modern logging practices all share a common impact on the landscape. What is it?

Back 112

Creation of a landscape mosaic

Front 113

113. Using this system, a researcher can bring together diverse sets of geographic information to quantify characteristics of the landscape mosaic and to determine how organisms are affected by landscape characteristics.

Back 113

GIS

Front 114

114. Two habitat patches of the same area differ in their shapes. One is circular, the other narrowly elliptical. Which has the greater ratio of edge to interior?

Back 114

Narrowly elliptical patch

Front 115

116. The degree of resolution at which an organism experiences variation in the landscape is referred to as: [ALSO A CLICKER QUESTION]

Back 115

Grain

Front 116

117. The "greenhouse effect" that may cause global warming appears to be associated with:

Back 116

An increase in atmospheric CO2 concentration

Front 117

118. If you were studying an animal, like the wildebeest, which covers huge areas in its annual movements, you would probably opt for a study that examined landscape features at relatively coarse (and/or large):

Back 117

Grain and extent

Front 118

119. Denitrification is an important biological process because:

Back 118

All of the above [it results in the release of nitrogen in a form unavailable to plants, it can proceed in waterlogged, anaerobic soils and sediments, it results in the breakdown of organic matter in soils and sediments, it is carried out by certain bacteria.

Front 119

120. The transformation of the forest dominated landscape in Minnesota to a landscape dominated by beaver ponds and wet/moist meadows during the comeback of beaver population in 1926-1986 is an examples of __________.

Back 119

The effect of landscape process on landscape structure

Front 120

121. Some amphibians and insects spend their larval stages in aquatic habitats and then range more widely across a variety of terrestrial and aquatic habitats as adults. As these organisms transition from their larval to adult stages, ecologists must __________ the extent of the landscape within which they attempt to understand the ecology of these species.

Back 120

Expand

Front 121

122. Nitrogen is made available to food webs by:

Back 121

Fixation

Front 122

123. The study of the effects of animal activities on landscape structure in Minnesota in 1926-1986 shows that..

Back 122

The increase in beaver population led to decreased forest cover and increased wet/moist meadows cover

Front 123

124. In the study of the role of road corridors in enhancing seed dispersal, seeds of _______ different plant species were uncovered in a car wash in Australia

Back 123

about 260

Front 124

125. About how many species of plants and animals worldwide have been described and given Latin names?

Back 124

1.5 million

Front 125

126. About how many species of plants and animals exist on the planet?

Back 125

10 million

Front 126

127. The present rate of extinction on Earth falls within what scientists consider the “background” or “normal” rate of extinction.

Back 126

False

Front 127

128. Researchers Tilman and Downing have demonstrated which of the following?

Back 127

More stable biomass production during drought in high-diversity systems

Front 128

129. An area that has a large number of unique species found nowhere else is said to possess a high level of:

Back 128

Endemism

Front 129

131. Which of the following is encompassed by the term biodiversity?
*The diversity of species on Earth
*The diversity of ecosystems and biomes on Earth
*The diversity of evolutionary lineages (taxonomic groups) on Earth
*All of the above

Back 129

All of the above

Front 130

132. Which of the following is encompassed by the term biodiversity?
*All of the species found within a given community
*All of the ecosystems found within a landscape
*All of the communities found within an ecosystem
*All of the above

Back 130

All of the above

Front 131

133. The height of young aspen _______as a result of reintroduction of wolves in Yellowstone and _______ trophic cascades.

Back 131

Increased...Top-down

Front 132

134. Which of the following is a reason we should care about the extinction of species and work to conserve biological diversity?
*Moral responsibility
*Economic benefits
*Value of species as indicators of environmental quality
*Value of species in maintaining ecosystem function
*All of the above

Back 132

All of the above

Front 133

135. Which of the following statements is most accurate about patterns of overexploitation.

Back 133

Overexploitation of species has been documented throughout the world.

Front 134

136. Habitat fragmentation poses severe threats to many species because of:
*Small size of local populations
*undesirable edge effects
*movement in response to changing conditions
*all of the above

Back 134

All of the above

Front 135

137. The immediate threat posed by the pesticide DDT to predatory birds is:

Back 135

Overly thin eggshells and deaths of embryos

Front 136

138. 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?

Back 136

Illegal poaching by ivory hunters

Front 137

139. How many nonindigenous species have been introduced to the United States?:

Back 137

50,000

Front 138

140. What was the name of the person who wrote the book that alerted the public to concerns related to the widespread use of pesticides such as DDT?

Back 138

Rachel Carson

Front 139

141. In the example of the biological magnification of DDT in a lake ecosystem, what is the order of DDT concentration in different groups of organisms?

Back 139

algae/plants, plant-eating (small) fish, fish-eating fish (large), large fish-eating birds

Front 140

142. In the United States, purple loosestrife, Japanese and Amur honeysuckle, Australian Melaleuca, and Brazilian pepper are all:

Back 140

Exotic flowering plants that have cause significant problems for native species

Front 141

143. What is a good estimate of the background rate of species extinction?

Back 141

One species per year

Front 142

144. What is the term that describes the process whereby formerly continuous areas (such as forests) are increasingly subdivided by roads, developments, agricultural areas, etc.

Back 142

Habitat fragmentation

Front 143

145. What fraction of medical prescriptions filled in the United States are drugs extracted directly from flowering plants? [ALSO A CLICKER QUESTION]

Back 143

One-quarter

Front 144

146. Large, flightless birds called _______ were exterminated from New Zealand by Maori natives before Europeans arrived.

Back 144

Moas

Front 145

147. The value of pollination services from wild pollinators in the U.S. alone is estimated at _____ dollars per year.

Back 145

4-6 billion

Front 146

148. Extinction is a normal process that occurs naturally in species.

Back 146

True

Front 147

149. Willow growth _____ as a result of reintroduction of wolves in Yellowstone and ______ trophic cascades

Back 147

Increased...top-down

Front 148

150. Which of the following is an appropriate goal for conservation?
*protecting a variety of geographic areas
*protecting endemic species
*protecting habitats and areas of special biological interest
*protecting large areas of intact habitat
*All of the above

Back 148

all of the above

Front 149

151. FTY hotspots tend to have above-average densities of human populations combined with high human population growth rates.

Back 149

True

Front 150

152. The benefits of many pesticides are often short-lived, and their amounts must be increased for continued effectiveness because:

Back 150

They select for evolution of resistance in target organisms.

Front 151

153. How do invasive species arrive in new areas?
*Deliberately as crops, ornamentals or game species
*Accidentally, such as in ship ballasts
*Naturally
*All of the above

Back 151

All of the above

Front 152

154. The _____________ of DDT refers to the dramatic increase in DDT concentration along the food chain (algae/plants -> plant-eating fish -> large fish -> fish-eating birds).

Back 152

Biological magnification

Front 153

155. What percentage of species listed under the U.S. Endangered Species Act are threatened because of competition, predation, parasitism, and herbivory by introduced species?

Back 153

40%

Front 154

156. Which of the following species long thought extinct might still be around?

Back 154

IVORY BILLED WOODPECKER

Front 155

157. Which of the following ecosystem services is considered indirect and dependent more on maintenance of intact ecosystems and less on availability of particular species?

Back 155

PRODUCTION OF CLEAN AIR AND WATER

Front 156

158. Until Europeans began worldwide colonial activities about 500 years ago, humans had not introduced exotic species anywhere.

Back 156

FALSE

Front 157

159. Invasive species can be harmful in which role?

Back 157

All of the above (competitors, predators, disease)

Front 158

160. Conservation is an approach that uses the principles and experiences from which of the following fields?

Back 158

All of the above (ecology and other natural resource management fields, genetics, sociology and economics)

Front 159

161. In the example of the biological magnification of DDT in a lake ecosystem, there was roughly a/an _______ time increase from the DDT concentration in the water to the DDT concentration in the tissue of the fish-eating birds.

Back 159

1,000,000

Front 160

162. Which of the following countries has a predominantly alien flora and fauna?

Back 160

New Zealand

Front 161

163. About _____ of human food comes from plants pollinated by wild pollinators.

Back 161

1/3

Front 162

176. The present rate of extinction on Earth falls within what scientists consider the “background” or “normal” rate of extinction.

Back 162

FALSE

Front 163

177. What is a good estimate of the current rate of species extinction?

Back 163

One species per day

Front 164

178. Of the top 150 prescription drugs used in the U.S., 118 originate from natural sources:

Back 164

74 percent from plants, 18 percent from fungi, 5 percent from bacteria, and, 3 percent from one vertebrate