Deck 56: Conservation and Global Ecology

Question 1

Erwin and Scott used an insecticidal spray to remove insects from the top section of an L. seemannii tree and collect them from the forest floor. Using the data collected, Erwin projected that this entire tree, from top to bottom, is host to about 600 unique arthropod species, which were not found on any other tree species. While the researchers also identified 900 beetle species from the top section, the vast majority of them were known to be found on many other tree species. If there are approximately 50,000 species of tropical trees, and assuming that every tree hosts a similar number of unique species, which of the following would be the best quantitative method to roughly estimate the total number of arthropod species, globally?

A) Estimate the species density and then multiply by 50,000.
B) Multiply 600 by 50,000.
C) Multiply 50,000 by 900.
D) Add 900 to 600, and then multiply by 50,000.

Answer 1

B

Question 2

A parasitic fungus, Geomyces destructans, has decimated millions of bats in the United States since it was first observed in upstate New York in 2006. The disease has been named white-nose syndrome because of the white fungal hyphae that cover the bat upon infection. It is believed that this fungus was introduced from Europe by tourists entering into caves with hibernating bat populations. Which prediction most likely reflects changes that will occur in natural communities as a result of massive bat mortality?

A) increased animal populations as a result of niche availability
B) increased rodent populations as a result of an increase in flying insect populations
C) increased flying insect populations
D) decreased bird populations as the spread of the fungus infects other closely related species

Answer 2

C

Question 3

Suppose you attend a town meeting at which some experts tell the audience that they have performed a cost-benefit analysis of a proposed transit system that would probably reduce overall air pollution and fossil fuel consumption. The analysis, however, reveals that ticket prices will not cover the cost of operating the new system. As a biologist, you know that if ecosystem services had been included in the analysis, the experts might have arrived at a different conclusion. Which of the following best explains why ecosystem services are rarely included in economic analyses?

A) Federal laws of the United States exclude their inclusion in any cost benefit analysis.
B) They have a low value and are usually not cost effective.
C) Ecosystem services only take into account abiotic factors that affect local environments.
D) Their cost is difficult to estimate, and people take them for granted.

Answer 3

D

Question 4

Which of the following terms includes all of the others?

A) species diversity
B) biodiversity
C) genetic diversity
D) ecosystem diversity

Question 5

Which of the following observations provides the best evidence of a biodiversity crisis?

A) the incursion of a non-native species
B) increasing pollution levels
C) high rate of extinction
D) climate change

Question 6

If all individuals in the last remaining population of a particular frog species were all highly related, which type of diversity would be of greatest concern when planning to prevent the species from going extinct?

A) global diversity
B) local diversity
C) ecosystem diversity
D) genetic diversity

Question 7

Philippe Bouchet and colleagues conducted a massive survey of marine molluscs on the west coast of New Caledonia. For 20% of the total species that were located and identified, only a single specimen was found. Which of the following claims about the diversity of molluscs in this area is best supported by the evidence?

A) The west coast of New Caledonia is not an appropriate habitat for molluscs.
B) Many of the species from this 20% are probably rare.
C) They were not sampling uniformly throughout the area.
D) Many of the species from this 20% are most likely just dispersing through the area.

Question 8

Which of the following threats to biodiversity impacts a specific species at one time, but also has the capacity to impact many other species due food-web interactions?

A) introduced species
B) habitat destruction
C) increased levels of atmospheric carbon dioxide, a cause of global warming
D) overharvesting

Question 9

Which of the following statements regarding extinction is the most accurate?

A) A large percentage of species are immune from extinction; however, rates of extinction may increase with continued human impacts.
B) Extinctions occur only periodically, separated by long time spans with no extinctions.
C) Extinction is occurring at a similar rate now as compared to historical fossil evidence.
D) The small-population approach is inferior to the declining-population approach if the goal is to conserve the maximum number of species in a given region.

Question 10

Researchers have been studying a rare population of 87 voles in an isolated area. Ten voles from a larger population were introduced into this isolated population. Besides having ten more individuals, which of the following is another benefit of the addition?

A) Increasing the consumption of producers.
B) Strengthening competition between voles and thereby increasing the survival of the fittest.
C) Increasing the beneficial effects of genetic drift.
D) Increasing genetic diversity.

Question 11

Overharvesting encourages extinction and is most likely to affect?

A) animals that occupy a broad ecological niche
B) large animals with low intrinsic reproductive rates
C) most organisms that live in the oceans' coral reefs
D) edge-adapted species

Question 12

Which of the following is necessary in order to better comprehend the magnitude of current extinctions?

A) differentiate between plant extinction and animal extinction numbers
B) focus on identifying more species of mammals and birds
C) identify more of the yet unknown species of organisms on Earth
D) use the average extinction rates of vertebrates as a baseline

Question 13

Which of the following criteria must be met for a species to qualify as invasive?

A) endemic to the area, spreads rapidly, and displaces foreign species
B) introduced to a new area, spreads rapidly, and displaces native species
C) introduced to a new area, spreads rapidly, and displaces other invasive species
D) endemic to the area, spreads slowly, and displaces native species

Question 14

Which of the following best describes how introduced species can have deleterious effects on the biological communities they invade?

A) competing with native species for resources and displacing them
B) spreading rapidly in their new region
C) reducing erosion
D) increasing the biodiversity in their new region

Question 15

Which of the following best describes the biological significance of genetic diversity between populations?

A) Genes for traits conferring an advantage to local conditions are unlikely.
B) The population that is most fit would survive by competitive exclusion.
C) Genetic diversity reduces the probability of extinction.
D) Diseases and parasites are not spread between separated populations.

Question 16

Tropical forests are being converted to farm or pasture land at an alarming rate. The impact of the deforestation on the biodiversity of the ecosystem is a major focus of research and conservation efforts. Which of the following is a direct benefit to humans that best explains why these forests need to be preserved?

A) Biodiversity in the tropics increases the potential to store more carbon from the atmosphere.
B) Natural and undisturbed areas are important wildlife habitats.
C) The diversity could contain novel medications for consumers.
D) The plant diversity provides unique areas for ecotourism.

Question 17

Which of the following can be caused by nitrogen and sulfur oxide air pollutants, which are released during the burning of fossil fuels?

A) the death of fish in lakes
B) precipitation with a pH as high as 8.0
C) eutrophication of lakes
D) global temperature decrease

Question 18

Of the following ecosystem types, which have been impacted the most by humans?

A) wetland and riparian
B) desert and high alpine
C) taiga and second-growth forests
D) tundra and arctic

Question 19

Loss of biodiversity matters not only with regard to mammals or other vertebrates, but also to microbes. Which of the following best explains the importance of discovering and protecting microbes from extinction?

A) Microbes play a role in digestion.
B) Microbes may produce unique proteins useful in genetic research.
C) Microbes are much greater in species number than any other taxa on Earth.
D) Microbes may be the most sensitive to the next large extinction event.

Question 20

Which of the following is an ecosystem service that includes processes that increase the quality of the abiotic environment?

A) Keystone predators have a marked effect on species diversity.
B) Green plants and phytoplankton produce the oxygen we breathe.
C) Bees, flies, and wasps pollinate many plants.
D) The presence of dams improves flood control.

Question 21

Use the following figure to answer the question. Which of the following claims about the edge effect is the most consistent with the data shown in the figure?

A) Biomass declines along edges of forest fragments.
B) Biomass increases along the edges of forest fragments.
C) Species diversity decreases along the edges of forest fragments.
D) Fragmentation does not affect biomass.

Question 22

Which of the following is the biggest challenge with selecting a site for a reserve?

A) Making a proper selection is difficult because the environmental conditions of sites can change quickly.
B) Keystone species are difficult to identify in potential reserve sites.
C) Only lands that are not useful to human activities are available for reserves.
D) Most of the best sites are inaccessible by land transportation, so making roads to them is often prohibitively expensive.

Question 23

A land developer and several ecologists are discussing how a parcel of private land should be developed with housing, while also saving 20 hectares as natural habitat. The land developer suggests that the 20 hectares be divided into 20 separate 1-hectare areas, spread out across the area. The ecologists suggest that it would be better to have one intact parcel of 20 hectares on one side of the larger area. Which of the following arguments is accurate and would best support one of the two options for the 20-hectare natural habitat?

A) The single intact parcel would have a smaller amount of edge than the 20 separate parcels.
B) The isolated 1-hectare plots increase the ability of individuals to disperse from one habitat to another.
C) The isolated 1-hectare plots are less vulnerable to edge effects.
D) The single intact parcel will create more inbreeding in many species.

Question 24

Which of the following strategies was used to rescue Illinois prairie chickens from a recent extinction vortex?

A) determining the minimum viable population size by taking into account the effective population size
B) establishing a nature reserve to protect its habitat nesting grounds
C) introducing individuals from other populations to increase genetic variation
D) reducing the population size of its predators and competitors

Question 25

Which of the following is the main purpose of movement corridors?

A) To slow down the introduction of new individuals of a species into an area.
B) To slowly introduce a species to a new reserve.
C) To create more edge habitat in order to better preserve the reserve interior.
D) To connect two otherwise isolated populations.

Question 26

Brown-headed cowbirds utilize fragmented forests effectively by ________.

A) feeding on the fruits of shrubs that tend to grow at the forest/open-field interface
B) parasitizing the nests of forest birds and feeding on open-field insects
C) consuming the eggs of other species as well as insects and seeds in open fields
D) outcompeting other songbird species for access to nesting holes in old-growth trees

Question 27

Use the following figure to answer the question. Five new individuals were added to a small population of bighorn sheep in 1986, and ten more were added between 1990 and 1994. Based upon evidence in the figure, which of the following changes in this population can be attributed to the additions?

A) the population increased exponentially
B) the population increased in overall numbers
C) the population growth rate increased
D) the population growth rate continued to decline

Question 28

Easter Island is an isolated island in the Pacific, about 3,500 km from South America. Although there are no trees or forests on the island now, archeological studies, fossil pollen, and other data show that Easter Island was once home to forests containing giant palms and other trees. Which of the following factors best represents a potential cause of such a collapse?

A) Shade-tolerant understory species increased in diversity in the absence of the palm.
B) Soil erosion decreased in the absence of the palm.
C) The decline or removal of the palm trees may have reduced habitat quality for many other tree species.
D) Productivity increased, thereby increasing competition, in the palms' absence.

Question 29

Use the following figure to answer the question. Based on the species-area plot in the figure, if habitable area on an island were reduced from 10,000 square kilometers (km2) to 1,000 km2, roughly what percentage of the species would disappear?

A) 0.3 percent
B) 3 percent
C) 30 percent
D) 60 percent

Question 30

Use the following figure to answer the question. In looking at the species-area plot in the figure, what can be concluded?

A) The number of bird species increases linearly with island area.
B) Two island land areas do not correlate to the number of bird species.
C) Diversity is independent from island area.
D) The number of bird species increases exponentially with island area.

Question 31

Which one of the following is most likely to be a hot spot of biodiversity for birds?

A) Central America
B) Northern Europe
C) Central Australia
D) Eastern North America

Question 32

If the sex ratio in a population is significantly different from 50:50, then which of the following statements will always be accurate?

A) The population will enter the extinction vortex.
B) The genetic variation in the population will increase over time.
C) Modeling of the minimum viable population size will underestimate the actual population size.
D) The effective population size will be less than the actual population size.

Question 33

Which of the following is the most accurate statement about the current research regarding forest fragmentation?

A) Fragmented forests promote biodiversity because they result in the combination of forest-edge species and forest-interior species.
B) In fragmented forests, the number of forest-adapted species tend to decline and the number of edge species tend to increase.
C) Fragmented forests are the goal of conservation biologists who design wildlife reserves.
D) The disturbance of timber extraction causes the species diversity to increase because of the new habitats created.

Question 34

Which of the following nations has become a world leader in the establishment of zoned reserves?

A) Costa Rica
B) China
C) United States
D) Mexico

Question 35

Movement corridors can be harmful to certain species because they ________.

A) increase inbreeding
B) spread disease and parasites
C) increase genetic diversity
D) allow seasonal migration

Question 36

Which of the following is the most likely reason why establishing new nature reserves in current biodiversity hot spots may not necessarily the best choice?

A) hot spots are situated in remote areas not accessible to the public
B) their ecological importance makes land purchase very expensive
C) a hot spot helps conserve only a few species
D) changing environmental conditions may shift the location of the hot spot

Question 37

Which of the following factors could cause the largest increase in the effective population size of a species?

A) an increased number of males
B) an increase in the total population size
C) an increase in the number of breeding males and females
D) an increased number of females

Question 38

Which of the following is the primary difference between the small-population approach and the declining-population approach to biodiversity recovery?

A) The small-population approach seeks to increase the genetic diversity of a threatened population rather than address the environmental factors that caused the population's decline.
B) The small-population approach is considered by conservation biologists when population numbers fall below 500.
C) The declining-population approach would likely involve bringing together individuals from scattered, small populations to interbreed in order to promote genetic diversity.
D) The small-population approach would investigate and eliminate all of the human impacts on the habitat of the species being studied for recovery.

Question 39

Which of the following conditions is the most likely indicator of a population in an extinction vortex?

A) The species in question is found only in small, stable pockets of its former range.
B) The effective population size of the species falls below 1,000.
C) Genetic measurements indicate a loss of genetic variation over time.
D) The population is declining and remains permanently small.

Question 40

Which of the following strategies would most rapidly increase the genetic diversity of a population in an extinction vortex?

A) Capture all remaining individuals in the population for captive breeding followed by reintroduction to the wild.
B) Establish a reserve that protects the population's habitat.
C) Introduce new individuals from other populations of the same species.
D) Sterilize the least fit individuals in the population.

Question 41

Which of the following is an unintended ecological consequence of human waste that is processed in water treatment facilities, and then discharged as effluent in rivers near cities?

A) eutrophication of major river systems
B) sexual differentiation abnormalities in aquatic organisms
C) PCB accumulation in river systems, wetlands, and lakes
D) temperature fluctuations that cause rivers to cool excessively

Question 42

Which of the following is accurate about polychlorinated biphenyls (PCBs)?

A) PCBs are naturally generated through biological interactions, but also synthesized industrially.
B) PCBs greatly affect the biomass of plants, which rely on nitrogen fixation.
C) PCBs accumulate in river systems via agricultural run-off.
D) PCBs, such as DDT, are beneficial in their role of saving human lives.

Question 43

Which of the following is a consequence of biological magnification?

A) Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers.
B) Populations of top-level predators are generally smaller than populations of primary consumers.
C) Only a small portion of the energy captured by producers is transferred to consumers.
D) The amount of biomass in the producer level of an ecosystem decreases if the producer turnover time increases.

Question 44

Which of the following pairs of human actions have caused the greatest number of extinctions on record and is predicted to cause the greatest number of future extinctions?

A) introduced species, habitat loss
B) habitat loss, overharvesting
C) climate change, habitat loss
D) habitat loss, climate change

Question 45

Which of the following factors causes extremely high levels of toxic chemicals in fish-eating birds?

A) acid precipitation
B) biological magnification
C) greenhouse effect
D) eutrophication

Question 46

Which of the following is the most common type of human debris found in the ocean?

A) plastic
B) wood
C) micro-metals such as aluminum fragments
D) glass

Question 47

Which of the following habitats would most likely have the highest species diversity?

A) ocean floor
B) a coral reef
C) a lagoon
D) an estuary

Question 48

Which of the following statements is supported by the scientific consensus on climate change?

A) Natural factors are primarily responsible for the current rise in global temperatures.
B) Deforestation and the clear-cutting of forests tends to reduce absorption of solar radiation and reduces global temperatures.
C) Plowing of fields creates dust which may increase global temperatures.
D) Changes in the Earth's orbit around the sun is primarily responsible for the current increase in global temperatures.

Question 49

During the inventory of bacterial genes present in the Sargasso Sea, a deep isolated area in the middle of the Atlantic Ocean, a research team concluded that at least 1,800 bacterial species were present. Because habitat structure is usually highly correlated with species diversity, what kind of bacterial diversity would you expect to observe in tropical coral reef waters?

A) slightly greater species diversity
B) slightly smaller species diversity
C) markedly smaller species diversity
D) markedly greater species diversity

Question 50

Which of the following best describes the relationship between habitat structure and biodiversity?

A) greater habitat structure is correlated with higher biodiversity
B) greater habitat structure is correlated with lower biodiversity
C) habitat structure and biodiversity are usually unrelated
D) habitats with moderate structure have the highest biodiversity

Question 51

Use the following graph and information to answer the question.
Flycatcher birds that migrate from Africa to Europe feed their chicks a diet that is almost exclusively moth caterpillars. The graph shows the peak dates of flycatcher arrival in Europe, bird hatching, and peak caterpillar season for the years 1980 and 2000. The y-axis is a measure of the abundance of birds, hatching chicks, and caterpillars.
The shift in the peak of caterpillar season is most likely due to ________.

A) earlier migration returns of flycatchers
B) an innate change in the biological clock of the caterpillars
C) global climate change
D) acid precipitation in Europe

Question 52

Which of the following is an accurate statement about the greenhouse effect?

A) although it initially intensified after global industrialization increased, it is currently undergoing a slow and steady reduction
B) the increasing concentration of CO₂ in the atmosphere are becoming relatively stabilized by carbon sequestration in plants that have increased photosynthetic outputs
C) living organisms are benefitted by the greenhouse effect
D) as the concentrations of greenhouse gases rise, less solar heat is retained and global temperatures cool

Question 53

Human-generated microplastics have thus been detected in all of the following places on Earth, except for ________.

A) the atmosphere
B) lakes and rivers
C) bedrock
D) supermarket fish

Question 54

Which of the following outcomes is caused by excessive nutrient runoff into aquatic ecosystems?

A) coral reef bleaching
B) acid precipitation
C) biological magnification
D) eutrophication

Question 55

Which of the following best describes a critical load?

A) the amount of nutrient augmentation necessary to bring a depleted habitat back to its former level
B) the level of a given toxin in an ecosystem that is lethal to 50 percent of the species present
C) the amount of added nutrient that can be absorbed by plants without damaging ecosystem integrity
D) the number of predators an ecosystem can support that effectively reduces prey populations to healthy levels

Question 56

Your friend is wary of environmentalists' claims that global climate change could lead to major biological change on Earth. Which of the following statements can you use in response to your friend's suspicions?

A) We know that atmospheric carbon dioxide has decreased over the past 170 years.
B) Through measurements and observations, we know that carbon dioxide levels and temperature fluctuations are indirectly correlated.
C) Global temperature changes are rising in all locations on the planet.
D) Scientist have recent evidence that climate change has severely degraded up to 2/3 of the Great Barrier Reef.

Question 57

Which of the following, if carefully monitored, could most reduce or prevent phytoplankton blooms in the Gulf of Mexico and formation of dead zone with low oxygen levels?

A) the amount of fertilizers applied to agricultural fields that the plants can absorb before nutrients start entering aquatic systems
B) the biomass of soybean plants that is gained via nitrogen fixation versus the amount gained due to fertilizer addition
C) the decomposition rate of soybean fields along major rivers, such as the Mississippi
D) the number of cattle grazing fields versus eating in feed lots at a ranch

Question 58

Which of the following is the most significant single contributor to the increase in the amount of carbon dioxide in Earth's atmosphere over the past 170 years?

A) increased worldwide primary production
B) an increase in the amount of infrared radiation absorbed by the atmosphere
C) the burning of fossil fuels
D) additional respiration by the rapidly growing human population

Question 59

Which of the following statements is best supported by the scientific consensus on factors affecting global warming?

A) Natural factors, such as Earths' tilt and orbit, are causing the increases in temperature over the last two centuries and therefore temperatures will begin to decrease over subsequent decades.
B) Deforestation and the clear-cutting of forests tend to increase the absorption of solar radiation and increases global temperatures.
C) If the burning of fossil fuel slowed significantly or even stopped, the drop in emissions would result in the cooling of Earth within a few years.
D) Solar cycles will continue to affect global temperatures in well-understood and predictable ways, yet Earth will continue to warm due to human activities.

Question 60

Agricultural lands frequently require nutrient augmentation because ________.

A) nitrogen-fixing bacteria are not as plentiful in agricultural soils because of the use of pesticides
B) the nutrients that become the biomass of plants are not cycled back to the soil on lands where they are harvested
C) land that is available for agriculture tends to be nutrient-poor
D) cultivation of agricultural land inhibits the decomposition of organic matter

Question 61

Use the following figure to answer the question. Functional groups are categories of plants, each containing numerous species, such as grasses and wildflowers, or trees and shrubs. Examine the figure and determine to what degree the data support the following hypothesis: Plant biomass increases with species richness.

A) The hypothesis is partially supported.
B) The hypothesis is fully supported.
C) The hypothesis is rejected.
D) The hypothesis can neither be rejected nor supported.

Question 62

Use the following figure to answer the question. Which of the following conclusions is best supported using the data in the figure?

A) As species richness changes, plant biomass remains consistent.
B) As species richness increases, plant biomass increases.
C) As species richness increases, plant biomass increases and then levels off.
D) As species richness decreases, plant biomass increases.

Question 63

Which of the following strategies would most rapidly increase the genetic diversity of a population in an extinction vortex?

A) Establish a reserve that protects the population's habitat.
B) Introduce new individuals transported from other populations of the same species.
C) Sterilize the least fit individuals in the population.
D) Control populations of the endangered population's predators and competitors.

Question 64

Which of the following is the primary goal of sustainable development?

A) involve more countries in conservation efforts
B) use only natural resources in the construction of new buildings
C) use natural resources such that they do not decline over time
D) reevaluate and re-implement management plans over time

Question 65

Eutrophication is often caused by excess limiting-nutrient runoff from agricultural fields into aquatic ecosystems. This process results in massive algal blooms that eventually die and decompose, ultimately depleting the dissolved oxygen, killing large numbers of fish and other aquatic organisms. Predict which of the following human actions would best address the problem of eutrophication near agricultural areas?

A) After each eutrophication event, remove the dead fish and invertebrates to place on agricultural fields instead of fertilizer.
B) Determine which limiting nutrient is responsible for the algal bloom, and use other fertilizers to apply to crops.
C) Remove the algae before it dies and decomposes to prevent eutrophication from occurring.
D) Determine critical nutrient loads required for certain crops, and do not exceed this amount during fertilizer application.

Question 66

What is the single greatest threat to biodiversity?

A) overharvesting of commercially important species
B) habitat alteration, fragmentation, and destruction
C) introduced species that compete with native species
D) novel pathogens

Question 67

The main cause of the increase in the amount of CO₂ in Earth's atmosphere over the past 170 years is ________.

A) increased worldwide primary production
B) increased worldwide fertilizer production
C) increased infrared radiation absorption by the atmosphere
D) the burning of fossil fuels and deforestation

Question 68

Which of the following statements about protected areas that have been established to preserve biodiversity is correct?

A) About 25 percent of Earth's land area is now protected.
B) Developing nations have a larger ecological footprint than developed nations, thus protected areas should be primarily established in developing nations.
C) Management of a protected area should be coordinated with management of the land surrounding the area.
D) It is only important to protect land within biodiversity hot spots.

Question 69

Use the graphs to answer the question. Copyright © 2003 American Institute of Biological Sciences. (Foster, D.R., F. Swanson et al., The importance of land-use and its legacies to ecology and environmental management. BioScience 53:77-88 [2003].)
Archeological, fossil, and geological data provide information on the Mayan populations and their environment in Mexico, in the Caribbean state of Yucatán. Based on the figure, what can you conclude about the history of land use in the southern Yucatán?

A) Massive soil erosion caused the Mayan population to crash.
B) Reduction in forest cover caused the Mayan population to crash.
C) As Mayan population increased, deforestation increased, probably leading to increased soil erosion.
D) This Mayan population practiced sustainable development.

Question 70

Which of the following possible actions by nations to reduce the warming of Earth's atmosphere would be best supported by the global scientific consensus?

A) drastically reducing human-based sources of CO₂ emissions
B) re-forestation of areas which have been logged or clear-cut
C) increasing the thickness of the ozone layer above Antarctica by reducing chlorine concentrations
D) restoring marine ecosystems in order to increase their absorption of carbon dioxide

Question 71

Use the following figure to answer the question.
Average Barrels of Oil Used per Person per Year
Examine the figure, which notes the average barrels of oil used per person per year in different countries. Which of the following is best supported by the data?

A) Residents in warmer climates use more energy per person.
B) Residents of more affluent, industrialized countries use more energy per person.
C) Residents of more populated countries use more energy per person.
D) English-speaking countries tend to use more energy per person.

Question 72

Which of these is a consequence of biological magnification?

A) Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers.
B) Populations of top-level predators are generally smaller than populations of primary consumers.
C) The biomass of producers in an ecosystem is generally higher than the biomass of primary consumers.
D) Only a small portion of the energy captured by producers is transferred to consumers.

Question 73

Which of the following statements about protected areas established to preserve biodiversity is true?

A) About 25% of Earth's land area is now protected.
B) National parks are the only type of protected area.
C) Management of a protected area does not need to be coordinated with management of the surrounding area.
D) It is especially important to protect biodiversity hot spots.

Question 74

One characteristic that distinguishes a population in an extinction vortex from most other populations is that ________.

A) its members are rare, top-level predators
B) its effective population size is lower than its total population size
C) its genetic diversity is very low
D) it is not well adapted to edge conditions

Question 75

Elevated carbon dioxide levels have been shown to contribute to the greenhouse effect, resulting in an increase in mean global temperature. Ecosystems where the largest warming has already occurred include snow-covered northern coniferous forests, tundra, and arctic sea ice habitats. Which statement best explains how the elimination of ice-covered ecosystems affects the rise or fall in global temperature?

A) Melting ice releases dissolved ozone gas, which adds to the greenhouse effect.
B) More reflective surfaces of ice are replaced with darker, more absorptive surfaces, thereby contributing to the warming trend.
C) Large-scale ice melts actually contribute toward lowering global temperatures by decreasing salinity of the oceans.
D) Carbon dioxide levels are lowered as a result of the greater volume of water to accommodate greater levels of dissolved gas.