BIO 1414 ch40-43
53) The feeding relationships among the species in a community determine the community's A) secondary succession. B) ecological niche. C) species richness. D) species-area curve. E) trophic structure.
Answer: E
60) Study the information in Figure 43.1 about quail habitats. Assuming that only one quail can occupy a habitat where all cover requirements are met, what is the maximum number of quail that could inhabit any of the hypothetical plots shown? A)1 B)2 C)4 D)6 E)9
Answer E
11) Evidence shows that some grasses benefit from being grazed. Which of the following terms would best describe this plant-herbivore interaction? A) mutualism B) commensalism C) parasitism D) competition E) predation
Answer: A
12) Deserts typically occur in a band around 30 degrees north and south latitude because A) descending air masses originating from the tropics tend to be dry. B) trade winds have little moisture. C) moisture-laden air is heavier than dry air and is not carried to these latitudes. D) ascending air from these regions tends to be moist, removing available water and creating a desert. E) these locations get the most intense solar radiation of any location on Earth.
Answer: A
13) Which of the following events might you predict to occur if the tilt of Earth's axis relative to its plane of orbit was increased to 33 1/2 degrees? A) Summers and winters in the United States would likely become warmer and colder, respectively. B) Winters and summers in Australia would likely become less distinct seasons. C) Seasonal variation at the equator might decrease. D) Both northern and southern hemispheres would experience summer and winter at the same time. E) Both poles would experience massive ice melts.
Answer: A
14) What is the biological significance of genetic diversity between populations? A) Genes for adaptive traits to local conditions make microevolution possible. B) The population that is most fit would survive by competitive exclusion. C) Genetic diversity allows for species stability by preventing speciation. D) Isolated populations become more fit. E) Diseases and parasites are not spread between separated populations.
Answer: A
16) What percentage of solar radiation striking a plant is converted into chemical energy? A) 1% B) 10% C) 25% D) 50% E) 100%
Answer: A
17) Generalized global air circulation and precipitation patterns are caused by A) rising, warm, moist air masses that cool and release precipitation as they rise and then, at high altitude, cool and sink back to the surface as dry air masses after moving north or south of the tropics. B) air masses that are dried and heated over continental areas that rise, cool aloft, and descend over oceanic areas followed by a return flow of moist air from ocean to land, delivering high amounts of precipitation to coastal areas. C) polar, cool, moist high-pressure air masses from the poles that move along the surface, releasing precipitation along the way to the equator where they are heated and dried. D) the revolution of Earth around the sun. E) mountain ranges that deflect air masses containing variable amounts of moisture.
Answer: A
18) Of the following ecosystem types, which have been impacted the most by humans? A) wetland and riparian B) open and benthic ocean C) desert and high alpine D) taiga and second-growth forests E) tundra and arctic
Answer: A
2) In ecosystems, why is the term cycling used to describe material transfer, whereas the term flow is used for energy exchange? A) Materials are repeatedly used, but energy flows through and out of ecosystems. B) Both material and energy are recycled and are then transferred to other ecosystems as in a flow. C) Materials are cycled into ecosystems from other ecosystems, but energy constantly flows within the ecosystem. D) Both material and energy flow in a never-ending stream within an ecosystem. E) None of the choices is correct.
Answer: A
20) Elephants are not the most dominant species in African grasslands, yet they influence community structure. The grasslands contain scattered woody plants, but they are kept in check by the uprooting activities of the elephants. Take away the elephants, and the grasslands convert to forests or to shrublands. The newly growing forests support fewer species than the previous grasslands. Which of the following describes why elephants are the keystone species in this scenario? A) Elephants exhibit a disproportionate influence on the structure of the community relative to their abundance. B) Grazing animals depend upon the elephants to convert forests to grassland. C) Elephants prevent drought in African grasslands. D) Elephants are the biggest herbivore in this community. E) Elephants help other populations survive by keeping out many of the large African predators.
Answer: A
21) According to bottom-up and top-down control models of community organization, which of the following expressions would imply that an increase in the size of a carnivore (C) population would negatively impact on its prey (P) population, but not vice versa? A) P ← C B) P → C C) C ↔ P D) P ← C → P E) C ← P → C
Answer: A
23) Biomanipulation can best be described as A) removing many of the organisms at the next higher trophic level so that the struggling trophic level below can recover. B) a means of reversing the effects of pollution by applying antidote chemicals that have a neutralizing effect on the community. C) an example of how one would use the bottom-up model for community restoration. D) adjusting the numbers of each of the trophic levels back to the numbers that they were before human disturbance. E) monitoring and adjusting the nutrient and energy flow through a community with new technologies.
Answer: A
24) Imagine five forest communities, each with 100 individuals distributed among four different tree species (W, X, Y, and Z). Which forest community would be most diverse? A) 25W, 25X, 25Y, 25Z B) 40W, 30X, 20Y, 10Z C) 50W, 25X, 15Y, 10Z D) 70W, 10X, 10Y, 10Z E) 100W, 0X, 0Y, 0Z
Answer: A
25) Aquatic primary productivity is most limited by which of the following? A) light and nutrient availability B) predation by primary consumers C) increased pressure with depth D) pollution E) temperature
Answer: A
26) Aquatic ecosystems are most likely to be limited by which of the following nutrients? A) nitrogen B) carbon C) potassium D) iron E) zinc
Answer: A
26) If a meteor impact or volcanic eruption injected a lot of dust into the atmosphere and reduced the sunlight reaching Earth's surface by 70% for one year, which of the following marine communities most likely would be least affected? A) deep-sea vent B) coral reef C) intertidal D) pelagic E) estuary
Answer: A
28) The primary difference between the small-population approach (S-PA) and the declining- population approach (D-PA) to biodiversity recovery is A) S-PA is interested in bolstering the genetic diversity of a threatened population rather than the environmental factors that caused the population's decline. B) S-PA kicks in for conservation biologists when population numbers fall below 500. C) D-PA would likely involve bringing together individuals from scattered small populations to interbreed in order to promote genetic diversity. D) S-PA would investigate and eliminate all of the human impacts on the habitat of the species being studied for recovery. E) D-PA would use recently collected population data to calculate an extinction vortex.
Answer: A
29) Why do moderate levels of disturbance result in an increase in community diversity? A) Habitats are opened up for less competitive species. B) Competitively dominant species infrequently exclude less competitive species after a moderate disturbance. C) The environmental conditions become optimal. D) The resulting uniform habitat supports stability, which in turn supports diversity. E) Less-competitive species evolve strategies to compete with dominant species.
Answer: A
3) In the ecological development of terrestrial biomes, which factor is most dependent on all the others? A) the species of colonizing animals B) prevailing temperature C) prevailing rainfall D) mineral nutrient availability E) soil structure
Answer: A
30) Which of the following lists of organisms is ranked in correct order from lowest to highest percent in production efficiency? A) mammals, fish, insects B) insects, fish, mammals C) fish, insects, mammals D) insects, mammals, fish E) mammals, insects, fish
Answer: A
33) An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square mile in one woodlot and 20 per square mile in another woodlot. What was the ecologist comparing? A) density B) dispersion C) carrying capacity D) cohorts E) range
Answer: A
35) Which of the following groups would be most likely to exhibit uniform dispersion? A) red squirrels, who actively defend territories B) cattails, which grow primarily at edges of lakes and streams C) dwarf mistletoes, which parasitize particular species of forest trees D) moths, in a city at night E) lake trout, which seek out cold, deep water high in dissolved oxygen
Answer: A
36) How does inefficient transfer of energy among trophic levels result in the typically high endangerment status of many top-level predators? A) Top-level predators are destined to have small populations that are sparsely distributed. B) Predators have relatively large population sizes. C) Predators are more disease-prone than animals at lower trophic levels. D) Predators have short life spans and short reproductive periods. E) Top-level predators are more likely to be stricken with parasites.
Answer: A
36) Which of the following studies would shed light on the mechanism of spread of H5N1 from Asia? A) Perform cloacal or saliva smears of migrating waterfowl to monitor whether any infected birds show up in Alaska. B) Test fecal samples for H5N1 in Asian waterfowl that live near domestic poultry farms in Asia. C) Test for the presence of H5N1 in poultry used for human consumption worldwide. D) Locate and destroy birds infected with H5N1 in Asian open-air poultry markets. E) Keep domestic and wild fowl from interacting with each other to minimize the probability that wild fowl could get infected and migrate out of Asia.
Answer: A
39) Which of the following sets of measurements would best describe a population's physical structure and vital statistics? A) density, dispersion, and demographics B) gene frequency over time and the ratio of reproductive to nonreproductive individuals C) annual precipitation averages and mean annual temperatures D) minimum and maximum amounts of precipitation and annual temperature extremes E) ratio of predators and the number of immigrants and emigrants
Answer: A
40) As the climate changes because of global warming, species' ranges of plants in the Northern Hemisphere may move northward, using effective reproductive adaptations to disperse their seeds. The trees that are most likely to avoid extinction in such an environment are those that A) have seeds that are easily dispersed by wind or animals. B) have thin seed coats. C) produce well-provisioned seeds. D) have seeds that become viable only after a forest fire. E) disperse many seeds in close proximity to the parent tree.
Answer: A
44) Consider the food chain grass → grasshopper → mouse → snake → hawk. How much of the chemical energy fixed by photosynthesis of the grass (100%) is available to the hawk? A) 0.01% B) 0.1% C) 1% D) 10% E) 60%
Answer: A
44) Which island in Figure 41.4 would likely have the greatest species diversity? A) A B) B C) C D) D E) E
Answer: A
46) The use of DDT as an insecticide in the United States has been outlawed since 1971, yet is still a problem for certain top-level carnivores in the United States. Which of the following choices best explains this apparent incongruity? A) DDT is still used for mosquito control in tropical countries, and certain migratory predators can be affected by a seasonal biomagnification. B) DDT is persistent in the environment, and all of the pre-1971 DDT is still available in toxic form to poison top-level carnivores. C) Pre-1971 DDT has been deposited in certain habitats, particularly wetlands and estuaries, so predators in these ecosystems are vulnerable to biomagnifications of DDT. D) Whereas most DDT-susceptible species have become resistant to persistent DDT, others are still vulnerable. E) All of the options are correct.
Answer: A
46) Which island in Figure 41.4 would likely have the lowest extinction rate? A) A B) B C) C D) D E) E
Answer: A
47) Which of the following locations is the main reservoir for nitrogen in Earth's nitrogen cycle? A) atmosphere B) sedimentary bedrock C) fossilized plant and animal remains (coal, oil, and natural gas) D) plant and animal biomass E) soil
Answer: A
48) Which of the following is the equation for zero population growth (ZPG)? A) b = m or r = 0 B) dN/dt = rN C) dN/dt = rmax N (K - N)/K D) dN/dt = rmax N E) dN/dt = 1.0N
Answer: A
4The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, — denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 52) What interactions exist between mycorrhizae and evergreen tree roots? A) +/+ B) +/o C) +/- D) o/o E) -/-
Answer: A
51) The biggest challenge that Costa Rica will likely face in its dedication to conservation and restoration in the future is A) the pressures of its growing population. B) its small size (as a country), which may not be able to maintain large enough reserves. C) the potential for disturbance of sensitive species in reserves by ecotourists. D) spread of disease and parasites via corridors from neighboring countries. E) the large number of Costa Rican species already in the extinction vortex.
Answer: A
52) Which of the following nations has become a world leader in the establishment of zoned reserves? A) Costa Rica B) Canada C) China D) United States E) Mexico
Answer: A
53) What is the first step in ecosystem restoration? A) to restore the physical structure B) to restore native species that have been extirpated due to disturbance C) to remove competitive invasive species D) to identify the limiting factors of the producers E) to remove toxic pollutants
Answer: A
54) In models of logistic population growth, A) the population growth rate slows dramatically as N approaches K. B) new individuals are added to the population most rapidly at the beginning of the population's growth. C) new individuals are added to the population as N approaches K. D) only density-dependent factors affect the rate of population growth. E) carrying capacity is never reached.
Answer: A
55) Which of the following relies upon existing biodiversity for the decontamination of polluted ecosystems? A) Some types of bacteria naturally convert toxins to less hazardous forms. B) Sawdust from lumber mills can be used to soak up chemicals that have saturated natural ecosystems. C) Species in contaminated areas may evolve into forms that can survive in contaminated soils. D) After centuries of agricultural production, soils depleted of nitrogen can be replenished by promoting the growth of nitrogen-fixing organisms.
Answer: A
58) Corn production in many states of the Midwest is limited by nitrogen levels in the soil. Some farmers reduce the need to apply expensive anhydrous ammonia to their fields by rotating corn crops with nitrogen-fixing soybean crops. Using soybeans to add nitrogen to soils is an example of A) biological augmentation. B) the biomass pyramid. C) promoting leaching efficiency. D) bioremediation. E) trophic efficiency.
Answer: A
58) The concept of sustainable development emphasizes A) the needs of future generations. B) trade between all nations of the world. C) the importance of developing the arts. D) the fastest ways to economic prosperity. E) the need for national government action.
Answer: A
59) Examine the food web for a particular terrestrial ecosystem in Figure 42.1. Which species is autotrophic? A) A B) B C) C D) D E) E
Answer: A
6) A cow's herbivorous diet indicates that it is a(n) A) primary consumer. B) secondary consumer. C) decomposer. D) autotroph. E) producer.
Answer: A
61) Which of the following is characteristic of K-selected populations? A) offspring with good chances of survival B) many offspring per reproductive episode C) small offspring D) a high intrinsic rate of increase E) early parental reproduction
Answer: A
62) Which variables define the ecological life history of a species? A) the age at which reproduction begins, frequency of reproduction, and the number of offspring for each reproductive episode B) the ratio of females to males, the length of the breeding season, and the number of offspring for each reproductive episode C) the number of offspring produced over a lifetime by a breeding pair and the survivability of the offspring D) timing breeding sessions with optimal environmental conditions and the number of offspring produced during each breeding session E) the amount of parental care given after birth, the number of reproductive episodes per year, and the number of years females are capable of producing viable offspring
Answer: A
63) 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 system when fuel, wages, and equipment are taken into account. As a biologist, you know that if ecosystem services had been included in the analysis the experts might have arrived at a different answer. Why are ecosystem services rarely included in economic analyses? A) Their cost is difficult to estimate and people take them for granted. B) They are not worth much and are usually not considered. C) There are no laws that require investigation of ecosystem services in environmental planning. D) There are too many variables to ecosystem services, making their calculation impossible. E) Ecosystem services only take into account abiotic factors that affect local environments.
Answer: A
64) If Figure 42.2 represents a marine food web, the smallest organism might be A) A. B) F. C) C. D) I. E) E.
Answer: A
66) Why do populations grow more slowly as they approach their carrying capacity? A) Density-dependent factors lead to fewer births and increased mortality. B) Density-independent factors lead to fewer births and increased mortality. C) Hormonal changes promote higher death rates in crowded populations. D) Individuals voluntarily stop mating so that overcrowding does not occur. E) The incoming energy decreases in populations experiencing a high rate of increase.
Answer: A
67) In the diagram of the nitrogen cycle in Figure 42.3, which number represents nitrogen- fixing bacteria? A) 5 B) 6 C) 7
Answer: A
68) Which climograph shows the climate for location 1 in Figure 40.1? A) A B) C C) E D) G E) H
Answer: A
68) Which of the following is a consequence of biological magnification? A) Toxic chemicals in the environment pose greater risk to toplevel 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. E) The amount of biomass in the producer level of an ecosystem decreases if the producer turnover time increases.
Answer: A
69) Of the following statements about protected areas that have been established to preserve biodiversity, which one is not correct? A) About 25% of Earth's land area is now protected. B) National parks are one of many types of protected areas. C) Most protected areas are too small to protect species. D) Management of a protected area should be coordinated with management of the land surrounding the area. E) It is especially important to protect biodiversity hot spots.
Answer: A
7) Which of the following choices includes all of the others in creating global terrestrial climates? A) differential heating of Earth's surface B) ocean currents C) global wind patterns D) evaporation of water from ocean surfaces E) Earth's rotation on its axis
Answer: A
7) Which of the following is an example of Müllerian mimicry? A) two species of unpalatable butterfly that have the same color pattern B) a day-flying hawkmoth that looks like a wasp C) a chameleon that changes its color to look like a dead leaf D) two species of rattlesnakes that both rattle their tails E) two species of moths with wing spots that look like an owl's eyes
Answer: A
78) Which curve best describes survivorship in elephants in Figure 40.3? A) A B) B C) C D) D E) E
Answer: A
8) According to the U.S. Endangered Species Act (ESA), the difference between an endangered species and a threatened one is that A) an endangered species is closer to extinction. B) a threatened species is closer to extinction. C) threatened species are endangered species outside the U.S. borders. D) endangered species are mainly tropical. E) only endangered species are vertebrates.
Answer: A
8) Which of the following terms encompasses all of the others? A) heterotrophs B) herbivores C) carnivores D) primary consumers E) secondary consumers
Answer: A
80) Which curve best describes survivorship in humans who live in developed nations in Figure 40.3? A) A B) B C) C D) D E) E
Answer: A
88) A population's carrying capacity A) may change as environmental conditions change. B) can be accurately calculated using the logistic growth model. C) generally remains constant over time. D) increases as the per capita growth rate (r) decreases. E) can never be exceeded.
Answer: A
89) When climbing a mountain, we can observe transitions in biological communities that are analogous to the changes A) in biomes at different latitudes. B) in different depths in the ocean. C) in a community through different seasons. D) in an ecosystem as it evolves over time. E) across the United States from east to west.
Answer: A
9) Which of the following is an example of aposematic coloration? A) the brightly colored patterns of poison dart frogs B) eye color in humans C) green color of a plant D) colors of an insect-pollinated flower E) a katydid whose wings look like a dead leaf
Answer: A
The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, — denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 49) What interactions exist between a bee and a flower? A) +/+ B) +/o C) +/- D) o/o E) -/-
Answer: A
The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, — denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 51) What interactions exist between cellulose-digesting organisms in the gut of a termite and the termite? A) +/+ B) +/o C) +/- D) o/o E) -/-
Answer: A
10) Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain nutrients and water from the vascular tissues of the trees. The trees derive no known benefits from the dwarf mistletoes. Which of the following best describes the interactions between dwarf mistletoes and trees? A) mutualism B) parasitism C) commensalism D) facilitation E) competition
Answer: B
10) Palm trees and subtropical plants are commonplace in Land's End, England, whose latitude is the equivalent of Labrador in coastal Canada, where the local flora is subarctic. Which statement best explains why this apparent anomaly exists between North America and Europe? A) Labrador does not get enough rainfall to support the subtropical flora found in Land's End. B) Regions such as Labrador are actually colder than England because colder arctic air is pulled down to eastern North America and not to England. C) Rainfall fluctuates greatly in England, rainfall is consistently high in Labrador. D) Labrador is too windy to support tall plants, such as palm trees. E) Labrador receives sunlight of lower duration and intensity than does Land's End.
Answer: B
11) The most serious consequence of a decrease in global biodiversity would be the A) increase in global warming and thinning of the ozone layer. B) potential loss of ecosystem services on which people depend. C) increase in the abundance and diversity of edge-adapted species. D) loss of sources of genetic diversity to preserve endangered species. E) loss of species for use as crops.
Answer: B
12) The major role of detritivores in ecosystems is to A) provide a nutritional resource for heterotrophs. B) recycle chemical nutrients to a form capable of being used by autotrophs. C) prevent the buildup of the organic remains of organisms, feces, and so on. D) return energy lost to the ecosystem by other organisms.
Answer: B
14) White-breasted nuthatches and Downy woodpeckers both eat insects that hide in the furrows of bark in hardwood trees. The Downy woodpecker searches for insects by hunting from the bottom of the tree trunk toward the top, whereas the white-breasted nuthatch searches from the top of the trunk down. These hunting behaviors best illustrate which of the following ecological concepts? A) competitive exclusion B) resource partitioning C) character displacement D) keystone species E) bottom-up and top-down hypotheses
Answer: B
15) Approximately 1% of the solar radiation that strikes a plant is converted into the chemical bond energy of sugars. Why is this amount so low? A) Approximately 99% of the solar radiation is converted to heat energy. B) Only 1% of the wavelengths of visible light is absorbed by photosynthetic pigments. C) Most solar energy strikes water and land surfaces. D) Approximately 99% of the solar radiation is reflected. E) Only the green wavelengths are absorbed by plants for photosynthesis.
Answer: B
15) The main reason polar regions are cooler than the equator is that A) there is more ice at the poles. B) sunlight strikes the poles at a lower angle. C) the poles are farther from the sun. D) the polar atmosphere is thinner and contains fewer greenhouse gases. E) the poles are permanently tilted away from the sun.
Answer: B
16) Overexploitation 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. D) terrestrial organisms more than aquatic organisms. E) edge-adapted species.
Answer: B
3) Which statement most accurately describes how matter and energy are used in ecosystems? A) Matter flows through ecosystems, energy cycles within ecosystems. B) Energy flows through ecosystems, matter cycles within and through ecosystems. C) Energy can be converted into matter, matter cannot be converted into energy. D) Matter can be converted into energy, energy cannot be converted into matter. E) Matter is used in ecosystems, energy is not.
Answer: B
18) Air masses formed over the Pacific Ocean are moved by prevailing westerlies where they encounter extensive north-south mountain ranges, such as the Sierra Nevadas and the Cascades. Which statement best describes the outcome of this encounter between a landform and an air mass? A) The cool, moist Pacific air heats up as it rises, releasing its precipitation as it passes the tops of the mountains, and this warm, now dry air cools as it descends on the leeward side of the range. B) The warm, moist Pacific air rises and cools, releasing precipitation as it moves up the windward side of the range, and this cool, now dry air mass heats up as it descends on the leeward side of the range. C) The cool, dry Pacific air heats up and picks up moisture from evaporation of the snowcapped peaks of the mountain range, releasing this moisture as precipitation when the air cools while descending on the leeward side of the range. D) These air masses are blocked by the mountain ranges, producing high annual amounts of precipitation on the windward sides of these mountain ranges. E) These air masses remain essentially unchanged in moisture content and temperature as they pass over these mountain ranges.
Answer: B
19) In a tide pool, 15 species of invertebrates were reduced to 8 after one species was removed. The species removed was likely a(n) A) pathogen. B) keystone species. C) herbivore. D) resource partitioner. E) mutualistic organism.
Answer: B
19) The introduction of the brown tree snake in the 1940s to the island of Guam has resulted in A) eradication of non-native rats and other undesirable/pest species. B) the extirpation of many of the island's bird and reptile species. C) a good lesson in biological control. D) a new species of hybrids from crossbreeding with a native snake species. E) its failure to compete with native species and its quick elimination from the island.
Answer: B
2) According to the competitive exclusion principle, two species cannot continue to occupy the same A) habitat. B) niche. C) territory. D) range. E) biome.
Answer: B
21) In which of the following terrestrial biome pairs are both dependent upon periodic burning? A) tundra and coniferous forest B) chaparral and savanna C) desert and savanna D) tropical forest and temperate broadleaf forest E) grassland and tundra
Answer: B
21) The total biomass of photosynthetic autotrophs present in an ecosystem is known as A) gross primary productivity. B) standing crop. C) net primary productivity. D) secondary productivity. E) trophic efficiency.
Answer: B
22) Fire suppression by humans A) will always result in an increase in species diversity in a given biome. B) can change the species composition within biological communities. C) will result ultimately in sustainable production of increased amounts of forest products for human use. D) is necessary for the protection of threatened and endangered forest species. E) is a management goal of conservation biologists to maintain the healthy condition of forest communities.
Answer: B
22) Which of the following is a likely explanation for why invasive species take over communities into which they have been introduced? A) Invasive species are less efficient than native species in competing for the limited resources of the environment. B) Invasive species are not held in check by the predators and agents of disease that have always been in place for native species. C) Humans carefully select which species will outcompete nuisance native species. D) Invasive species have a higher reproductive potential than native species. E) Invasive species come from geographically isolated regions, so when they are introduced to regions where there is more competition, they thrive.
Answer: B
22) Which of the following species was driven to extinction by overexploitation by hunters/fishermen? A) African elephant B) the great auk C) North American bluefin tuna D) flying foxes E) American bison
Answer: B
23) Which of the following statements best describes the interaction between fire and ecosystems? A) The likelihood of a wildfire occurring in a given ecosystem is highly predictable over the short term. B) Many kinds of plants and plant communities have adapted to frequent fires. C) The suppression of forest fires by man has prevented certain communities, such as grasslands, from reaching their climax stage. D) Chaparral communities have evolved to the extent that they rarely burn. E) Fire is unnatural in ecosystems and should be prevented.
Answer: B
25) Which marine zone has the lowest rates of primary productivity (photosynthesis)? A) pelagic B) abyssal C) neritic D) continental shelf E) intertidal
Answer: B
27) The word triage originated during World War I and was first used by French doctors in prioritizing patients based on the severity of their wounds, because there were more wounded soldiers in need of urgent care than there were resources to treat them. Conservation biologists have to make similar determinations with degraded ecosystems. Which of the following is the most important consideration when it comes to managing for maintenance of biodiversity? A) identifying large, high-profile vertebrates first, because steps to saving them would be most recognized by the public B) determining which species is most important for conserving biodiversity as a whole C) replanting suitable habitat for fauna D) assessing the economic costs and the gains for society E) maintaining optimum size of all populations in the ecosystem
Answer: B
27) What is the primary limiting factor for aquatic productivity? A) pressure B) lack of nutrients C) light availability D) herbivores E) competition
Answer: B
27) Which statement describes how climate might change if Earth was 75% land and 25% water? A) Terrestrial ecosystems would likely experience more precipitation. B) Earth's daytime temperatures would be higher and nighttime temperatures lower. C) Summers would be longer and winters shorter at midlatitude locations. D) Earth would experience an unprecedented global warming. E) More terrestrial microclimates would be created because of daily fluctuations in climate.
Answer: B
3) Which of the following best describes resource partitioning? A) competitive exclusion that results in the success of the superior species B) slight variations in a species' niche that allow similar species to coexist C) two species that can coevolve to share identical niches D) differential resource utilization that results in a decrease in community species diversity E) a climax community that is reached when no new niches are available
Answer: B
30) Managing southeastern forests specifically for the red-cockaded woodpecker A) required the growth of a dense understory of trees and shrubs. B) contributed to greater abundance and diversity of other forest bird species. C) caused other species of songbird to decline. D) involved strict fire-suppression measures. E) involved the creation of fragmented forest habitat.
Answer: B
30) Species richness increases A) as we increase in altitude in equatorial mountains. B) as we travel southward from the North Pole to the equator. C) on islands as distance from the mainland increases. D) as depth increases in aquatic communities. E) as community size decreases.
Answer: B
31) There are more species in tropical areas than in places more distant from the equator. This is probably a result of A) fewer predators. B) more intense annual solar radiation. C) more frequent ecological disturbances. D) fewer agents of disease. E) fewer predators, more intense annual solar radiation, more frequent ecological disturbances, and fewer agents of disease.
Answer: B
31) Which of the following is true about the current research regarding forest fragmentation? A) Fragmented forests support a greater biodiversity because they result in the combination of forest-edge species and forest-interior species. B) Fragmented forests support a lesser biodiversity because the forested-adapted species leave, and only the edge and open-field species can occupy fragmented forests. C) Fragmented forests are the goal of conservation biologists who design wildlife preserves. D) Harvesting timber that results in forest fragmentation results in less soil erosion. E) The disturbance of timber extraction causes the species diversity to increase because of the new habitats created.
Answer: B
35) 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) roosting in forest trees, and nesting in grassy fields. D) outcompeting other songbird species in fragmented communities. E) using forest cover to escape from predators in their normal grassland habitat.
Answer: B
35) Zoonotic disease A) is caused by suborganismal pathogens such as viruses, viroids, and prions only. B) is caused by pathogens that are transferred from other animals to humans by direct contact or by means of a vector. C) can only be spread from animals to humans through direct contact. D) can only be transferred from animals to humans by means of an intermediate host. E) is too specific to study at the community level, and studies of zoonotic pathogens are relegated to organismal biology.
Answer: B
37) Trophic efficiency is A) the ratio of net secondary production to assimilation of primary production. B) the percentage of production transferred from one trophic level to the next. C) a measure of how nutrients are cycled from one trophic level to the next. D) usually greater than production efficiencies. E) about 90% in most ecosystems.
Answer: B
39) The oak tree pathogen Phytophthora ramorum has migrated 800 km in 15 years. West Nile virus spread from New York State to 46 other states in 5 years. The difference in the rate of spread is probably related to A) the lethality of each pathogen. B) the mobility of their hosts. C) the fact that viruses are very small. D) innate resistance. E) dormancy viability.
Answer: B
4) The law of conservation of matter states that matter cannot be created, yet matter is sometimes gained or lost to an ecosystem. What is the reason for this seeming contradiction? A) Chemoautotrophic organisms can convert matter to energy. B) Ecosystems are open systems, therefore, matter can be moved in/out of an ecosystem from/to another ecosystem. C) Photosynthetic organisms convert sugars to more complex organic molecules. D) Detrivores convert matter to energy. E) Heterotrophs convert heat to energy.
Answer: B
40) For most terrestrial ecosystems, pyramids composed of species abundances, biomass, and energy are similar in that they have a broad base and a narrow top. The primary reason for this pattern is that A) secondary consumers and top carnivores require less energy than producers. B) at each step, energy is lost from the system because of the second law of thermodynamics. C) as matter passes through ecosystems, some of it is lost to the environment. D) biomagnification of toxic materials limits the secondary consumers and top carnivores. E) top carnivores and secondary consumers have a more general diet than primary producers.
Answer: B
40) Which of the following scenarios would provide the most legitimate data on population density? A) Count the number of nests of a particular species of songbird and multiply this by a factor that extrapolates these data to actual animals. B) Count the number of pine trees in several randomly selected 10-m by 10-m plots and extrapolate this number to the fraction of the study area these plots represent. C) Use the mark-and- recapture method to estimate the size of the population. D) Calculate the difference between all of the immigrants and emigrants to see if the population is growing or shrinking. E) Add the number of births and subtract the individuals that die to see if the population's density is increasing or decreasing.
Answer: B
41) If global warming continues at its present rate, which biomes will likely take the place of the coniferous forest (taiga)? A) tundra and polar ice B) temperate broadleaf forest and grassland C) desert and chaparral D) tropical forest and savanna E) chaparral and temperate broadleaf forest
Answer: B
42) Which of the following investigations would shed the most light on the future distribution of organisms in temperate regions that are faced with climate change? A) Remove, to the mineral soil, all of the organisms from an experimental plot and monitor the colonization of the area over time in terms of both species diversity and abundance. B) Look at the climatic changes that occurred since the last ice age and how species redistributed as glaciers melted, then make predictions on future distribution in species based on past trends. C) Compare and contrast the flora and fauna of warm/cold/dry/wet climates to shed light on how they evolved to be suited to their present-day environment. D) Quantify the impact of humankind's activities on present-day populations of threatened and endangered species to assess the rate of extirpation and extinction. E) There is no scientific investigation that can help make predictions on the future distribution of organisms.
Answer: B
43) Which letter represents an organism that could be a producer in Figure 41.3? A) A B) B C) C D) D E) E
Answer: B
44) What is the biggest problem with selecting a site for a preserve? A) There is always a conflict about use of land set aside for preservation. B) Making a proper selection is difficult because the current environmental conditions of almost any site may change in the future because of climate change or other factors. C) Keystone species are difficult to identify in potential preserve sites. D) Only lands that are not useful to human activities are available for preserves. E) Most of the best sites are inaccessible by land transportation, so making roads to them is often prohibitively expensive.
Answer: B
45) A population of ground squirrels has an annual per capita birth rate of 0.06 and an annual per capita death rate of 0.02. Calculate an estimate of the number of individuals added to (or lost from) a population of 1,000 individuals in one year. A) 120 individuals added B) 40 individuals added C) 20 individuals added D) 400 individuals added E) 20 individuals lost
Answer: B
46) Exponential growth of a population is represented by dN/dt = A) rN/K B) rmax N C) rN (K + N) D) rN (K - N)/K E) rN (N - K)/K
Answer: B
47) 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) grains raised for feeding livestock must be fortified, and thus require additional nutrients. E) cultivation of agricultural land inhibits the decomposition of organic matter.
Answer: B
5) Resource partitioning would be most likely to occur between A) sympatric populations of a predator and its prey. B) sympatric populations of species with similar ecological niches. C) sympatric populations of a flowering plant and its specialized insect pollinator. D) allopatric populations of the same animal species. E) allopatric populations of species with similar ecological niches.
Answer: B
51) Which of the following statements is correct about biogeochemical cycling? A) The phosphorus cycle involves the recycling of atmospheric phosphorus. B) The phosphorus cycle involves the weathering of rocks. C) The carbon cycle is a localized cycle that primarily involves the burning of fossil fuels. D) The carbon cycle has maintained a constant atmospheric concentration of CO2 for the past million years. E) The nitrogen cycle involves movement of diatomic nitrogen between the biotic and abiotic components of the ecosystem.
Answer: B
53) As N approaches K for a certain population, which of the following is predicted by the logistic equation? A) The growth rate will not change. B) The growth rate will approach zero. C) The population will show an Allee effect. D) The population will increase exponentially. E) The carrying capacity of the environment will increase.
Answer: B
54) What is the goal of restoration ecology? A) to replace a ruined ecosystem with a more suitable ecosystem for that area B) to speed up the restoration of a degraded ecosystem C) to completely restore a disturbed ecosystem to its former undisturbed state D) to prevent further degradation by protecting an area with park status E) to manage competition between species in human-altered ecosystems
Answer: B
55) Carrying capacity is A) seldom reached by marine producers and consumers because of the vast resources of the ocean. B) the maximum population size that a particular environment can support. C) fixed for most species over most of their range most of the time. D) determined by density and dispersion data. E) the term used to describe the stress a population undergoes due to limited resources.
Answer: B
56) Which of the following best illustrates human efforts to improve environmental sustainability? A) rerouting major highways around cities to avoid traffic congestion B) increasing our reliance on renewable sources of energy C) upgrading computers every few years to improve performance D) converting automobiles from gasoline to natural gas as a new source of fuel
Answer: B
59) Which of the following pairs of reproductive strategies is consistent with energetic trade-off and reproductive success? A) Pioneer species of plants produce many very small, highly airborne seeds, whereas large elephants that are very good parents produce many offspring. B) Female rabbits that suffer high predation rates may produce several litters per breeding season, and coconuts produce few fruits, but most survive when they encounter proper growing conditions. C) Species that have to broadcast to distant habitats tend to produce seeds with heavy protective seed coats, and animals that are caring parents produce fewer offspring with lower infant mortality. D) Free-living insects lay thousands of eggs and provide no parental care, whereas flowers take good care of their seeds until they are ready to germinate. E) Some mammals will not reproduce when environmental resources are low so they can survive until conditions get better, and plants that produce many small seeds are likely found in stable environments.
Answer: B
6) Which of the following levels of ecological organization is arranged in the correct sequence from most to least inclusive? A) community, ecosystem, individual, population B) ecosystem, community, population, individual C) population, ecosystem, individual, community D) individual, population, community, ecosystem E) individual, community, population, ecosystem
Answer: B
61) Examine the food web for a particular terrestrial ecosystem in Figure 42.1. Species C is toxic to predators. Which species is most likely to benefit from being a mimic of C? A) A B) B C) C D) D E) E
Answer: B
63) Which pattern of reproduction is correctly paired with a species? A) iteroparity—Pacific salmon B) iteroparity—elephant C) semelparity—oak tree D) semelparity—rabbit E) semelparity—polar bear
Answer: B
65) Which of the following is most likely to contribute to density-dependent regulation of populations? A) the removal of toxic waste by decomposers B) intraspecific competition for nutrients C) earthquakes D) floods E) fires
Answer: B
67) Which of the following could be a density-independent factor limiting human population growth? A) social pressure for birth control B) earthquakes C) plagues D) famines E) pollution
Answer: B
68) In the diagram of the nitrogen cycle in Figure 42.3, which number represents nitrifying bacteria? A) 5 B) 6 C) 7
Answer: B
7) To recycle nutrients, an ecosystem must have, at a minimum, A) producers. B) producers and decomposers. C) producers, primary consumers, and decomposers. D) producers, primary consumers, secondary consumers, and decomposers. E) producers, primary consumers, secondary consumers, top carnivores, and decomposers.
Answer: B
7) Which of the following terms includes all of the others? A) species diversity B) biodiversity C) genetic diversity D) ecosystem diversity E) species richness
Answer: B
70) A porcupine eats 3,000 J of plant material. Of this, 2,100 J is indigestible and is eliminated as feces, 800 J are used in cellular respiration, and 100 J are used for growth and reproduction. What is the approximate production efficiency of this animal? A) 0.03% B) 3% C) 11% D) 27% E) 33%
Answer: B
72) Which climograph shows the climate for location 5 in Figure 40.1? A) A B) C C) D D) E E) H
Answer: B
73) Which of these ecosystems has the lowest net primary production per square meter? A) a salt marsh B) an open ocean C) a coral reef D) a grassland E) a tropical rain forest
Answer: B
75) Which zone produces the most global oxygen in Figure 40.2? A) A B) B C) C D) D E) E
Answer: B
The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, — denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 47) What interactions exist between the cattle egret and grazing cattle? A) o/- B) +/o C) +/- D) o/o E) -/-
Answer: B
1) How do the Taylor Glacier bacteria produce their energy? A) photosynthesis B) heterotrophism C) chemoautotrophism D) thermophobism E) photoautotrophism
Answer: C
1) Trees are rare in the savanna biome because of A) insufficient annual precipitation. B) acidic soils. C) extreme winter temperatures. D) large variations in seasonal rainfall. E) permafrost.
Answer: C
1) Which of the following ecological locations has the greatest species diversity? A) tundra B) deciduous forests C) tropical rain forest D) grasslands E) islands
Answer: C
10) If the sun were to suddenly stop providing energy to Earth, most ecosystems would vanish. Which of the following ecosystems would likely survive the longest after this hypothetical disaster? A) tropical rain forest B) tundra C) deep-sea vent community D) grassland E) desert
Answer: C
11) Which of the following is true of detritivores? A) They recycle chemical elements directly back to primary consumers. B) They synthesize organic molecules that are used by primary producers. C) They convert organic materials from all trophic levels to inorganic compounds usable by primary producers. D) They secrete enzymes that convert the organic molecules of detritus into CO2 and H2O. E) Some species are autotrophic, whereas others are heterotrophic.
Answer: C
14) Which of the following statements is true? A) An ecosystem's trophic structure determines the rate at which energy cycles within the system. B) At any point in time, it is impossible for consumers to outnumber producers in an ecosystem. C) Chemoautotrophic prokaryotes near deep-sea vents are primary producers. D) There has been a well-documented increase in atmospheric nitrogen over the past several decades. E) The reservoir of ecosystem phosphorous is the atmosphere.
Answer: C
15) Which statement best describes the evolutionary significance of mutualism? A) Mutualism offers more biodiversity to a community. B) Individuals partaking in a mutualistic relationship are more resistant to parasites. C) Interaction increases the survival and reproductive rates of mutualistic species. D) Mutualistic interaction lessens competition in communities where it is present. E) Mutualistic relationships allow organisms to synthesize and use energy more efficiently.
Answer: C
17) Subtraction of which of the following will convert gross primary productivity into net primary productivity? A) the energy contained in the standing crop B) the energy used by heterotrophs in respiration C) the energy used by autotrophs in respiration D) the energy fixed by photosynthesis E) all solar energy
Answer: C
18) How did Eugene Odum describe an ecological niche? A) the "address" of an organism B) an entity that is synonymous with an organism's specific trophic level C) an organism's "profession" in the community D) the organism's role in recycling nutrients in its habitat E) the interactions of the organism with other members of the community
Answer: C
2) Invasive species are introduced by humans to new geographic locations and A) are successful in colonizing a novel area. B) spread because they encounter none of their natural predators. C) All of the choices are correct. D) can outcompete and displace native species for biotic and abiotic resources. E) are usually considered pests by ecologists.
Answer: C
2) Which of the following statements best describes the effect of climate on biome distribution? A) Average annual temperature and precipitation are sufficient to predict which biome will be found in an area. B) Seasonal fluctuation of temperature is not a limiting factor in biome distribution if areas have the same annual temperature and precipitation means. C) Not only is the average climate important in determining biome distribution, but so is the pattern of climatic variation. D) Temperate forests and grasslands are different biomes because they receive a different quality and quantity of sunlight, even though they have essentially the same annual temperature and precipitation. E) Correlation of climate with biome distribution is sufficient to determine the cause of biome patterns.
Answer: C
22) How is it that the open ocean produces the highest net primary productivity of Earth's ecosystems, yet net primary productivity per square meter is relatively low? A) Oceans contain greater concentrations of nutrients compared to other ecosystems. B) Oceans receive a lesser amount of solar energy per unit area. C) Oceans have the largest area of all the ecosystems on Earth. D) Ocean ecosystems have less species diversity. E) Oceanic producers are generally much smaller than oceanic consumers.
Answer: C
23) Why is net primary production (NPP) a more useful measurement to an ecosystem ecologist than gross primary production (GPP)? A) NPP can be expressed in energy/unit of area/unit of time. B) NPP can be expressed in terms of carbon fixed by photosynthesis for an entire ecosystem. C) NPP represents the stored chemical energy that will be available to consumers in the ecosystem. D) NPP is the same as the standing crop. E) NPP shows the rate at which the standing crop is utilized by consumers.
Answer: C
24) How is net ecosystem production (NEP) typically estimated in ecosystems? A) the ratio of producers to consumers B) the amount of heat energy released by the ecosystem C) the net flux of CO2 or O2 in or out of an ecosystem D) the rate of decomposition by detritivores E) the annual total of incoming solar radiation per unit of area
Answer: C
24) Review the formula for effective population size. Imagine a population of 1,000 small rodents. Of these, 300 are breeding females, 300 are breeding males, and 400 are nonbreeding juveniles. What is the effective population size? A) 1,000 B) 1,200 C) 600 D) 400 E) 300
Answer: C
25) Why are food chains relatively short? A) Top-level feeders tend to be more numerous than lower-trophic- level species. B) Top-level feeders tend to be small but are capable of conserving more energy. C) Longer chains are less stable and energy transfer between trophic levels is inefficient. D) There are only so many organisms that are adapted to feed on other types of organisms. E) Food chain length is ultimately determined by the photosynthetic efficiency of producers.
Answer: C
28) The 1988 Yellowstone National Park lodgepole pine forest fires were likely the result of A) overgrazing by elk. B) infrequent rain episodes. C) years of fire suppression by humans. D) unextinguished campfires. E) geysers.
Answer: C
28) Which of the following ecosystems would likely have a larger net primary productivity/hectare, and why? A) open ocean because of the total biomass of photosynthetic autotrophs B) a temperate grassland because of the small standing crop biomass that results from consumption by herbivores and rapid decomposition C) tropical rain forest because of the high species diversity D) cave due to the lack of photosynthetic autotrophs E) tundra because of the incredibly rapid period of growth during the summer season
Answer: C
28) Which of the following examples of an ecological effect leading to an evolutionary effect is most correct? A) When seeds are not plentiful, trees produce more seeds. B) A few organisms of a larger population survive a drought and then these survivors emigrate to less arid environments. C) A few individuals with denser fur survive the coldest days of an ice age, and the reproducing survivors of the ice age all have dense fur. D) Fish that swim the fastest in running water catch the most prey and more easily escape predation. E) The insects that spend the most time exposed to sunlight have the most mutations.
Answer: C
29) Which of the following are important biotic factors that can affect the structure and organization of biological communities? A) precipitation, wind B) nutrient availability, soil pH C) predation, competition D) temperature, water E) light intensity, seasonality
Answer: C
3) Estimates of current rates of extinction A) indicate that we have reached a state of stable equilibrium in which speciation rates equal extinction rates. B) suggest that one-half of all animal and plant species may be gone by the year 2100. C) indicate that rates may be greater than the mass extinctions at the close of the Cretaceous period. D) indicate that only 1% of all of the species that have ever lived on Earth are still alive. E) suggest that rates of extinction have decreased globally.
Answer: C
30) A certain species of pine tree survives only in scattered locations at elevations above 2,800 m in the western United States. To understand why this tree grows only in these specific places, an ecologist should A) conclude that lower elevations are limiting to the survival of this species. B) study the anatomy and physiology of this species. C) investigate the various biotic and abiotic factors that are unique to high altitude. D) analyze the soils found in the vicinity of these trees, looking for unique chemicals that may support their growth. E) collect data on temperature, wind, and precipitation at several of these locations for a year.
Answer: C
31) A 3-hectare lake in the American Midwest suddenly has succumbed to an algal bloom. What is the likely cause of eutrophication in freshwater ecosystems, such as this one? A) increased solar radiation B) introduction of non-native tertiary consumer fish C) nutrient-rich runoff D) accidental introduction of a prolific culture of algae E) iron dust blowing into the lake
Answer: C
32) A population is correctly defined as having which of the following characteristics? I. inhabiting the same general area II. belonging to the same species III. possessing a constant and uniform density and dispersion A) I only B) III only C) I and II only D) II and III only E) I, II, and III
Answer: C
32) According to the small-population approach, what would be the best strategy for saving a population from extirpation? A) determining the minimum viable population size by taking into account the effective population size B) establishing a nature reserve to protect its habitat C) introducing individuals from other populations to increase genetic variation D) determining and remedying the cause of its decline E) reducing the population size of its predators and competitors
Answer: C
33) Relatively small geographic areas with high concentrations of endemic species and a large number of endangered and threatened species are known as A) endemic sinks. B) critical communities. C) biodiversity hot spots. D) endemic metapopulations. E) bottlenecks.
Answer: C
34) How is habitat fragmentation related to biodiversity loss? A) Less carbon dioxide is absorbed by plants in fragmented habitats. B) In fragmented habitats, more soil erosion takes place. C) Populations of organisms in fragments are smaller, and thus more susceptible to extinction. D) Animals are forced out of smaller habitat fragments. E) Fragments generate silt that negatively affects sensitive river and stream organisms.
Answer: C
34) What is secondary production? A) energy converted by secondary consumers from primary consumers B) solar energy that is converted to chemical energy by photosynthesis C) food that is converted to new biomass by consumers D) energy that is not used by consumers for growth and reproduction E) growth that takes place during the second year of life in consumers
Answer: C
34) Which of the following best describes the consequences of white-band disease in Caribbean coral reefs? A) Staghorn coral has been decimated by the pathogen, and Elkhorn coral has taken its place. B) Key habitat for lobsters, snappers, and other reef fishes has improved. C) Algal species take the place of the dead coral, and the fish community is dominated by herbivores. D) Algal species take over and the overall reef diversity increases due to increases in primary productivity. E) Other coral species take the place of the affected Staghorn and Elkhorn species.
Answer: C
36) To construct a reproductive table for a sexual species, one needs to A) assess sperm viability for the males in the population. B) keep track of all of the offspring of a cohort. C) keep track of the females in a cohort. D) keep track of all of the offspring of the females in a cohort. E) analyze the ratio of deaths to births in a cohort.
Answer: C
36) Which of the following is consistent with forest fragmentation research? A) Productivity is the same in both fragmented forests and forest interiors. B) Edge communities consistently have low species diversity. C) Forest-interior species show declines in small patch communities. D) New-edge species that migrate in do not seem to compete with forest species and often increase biodiversity in fragmented forests. E) Species diversity is always lower in fragmented forests when compared to forest interiors in the same region.
Answer: C
37) How are movement corridors potentially harmful to certain species? A) They increase inbreeding. B) They promote dispersion. C) They spread disease and parasites. D) They increase genetic diversity. E) They allow seasonal migration.
Answer: C
38) Biodiversity hot spots are not necessarily the best choice for nature preserves because A) hot spots are situated in remote areas not accessible to wildlife viewers. B) their ecological importance makes land purchase very expensive. C) a hot spot for one group of organisms may not be a hot spot for another group. D) hot spots are designated by the abiotic factors present, not the biotic factors. E) designated hot spots change on a daily basis.
Answer: C
38) In terms of community ecology, why are pathogens often more virulent now than before? A) More new pathogens have recently evolved. B) Host organisms have become more susceptible because of weakened immune systems. C) Human activities are transporting pathogens into new habitats (or communities) at an unprecedented rate. D) Medicines for treating pathogenic disease are in short supply. E) Sequencing of genes in pathogenic organisms is particularly difficult.
Answer: C
38) Long-term studies of Belding's ground squirrels show that immigrants move nearly 2 km from where they are born and become 1-8% of the males and 0.7-6% of the females in other populations. On an evolutionary scale, why is this significant? A) These immigrants make up for the deaths of individuals, keeping the other populations' size stable. B) Young reproductive males tend to stay in their home population and are not driven out by other territorial males. C) These immigrants provide a source of genetic diversity for the other populations. D) Those individuals that emigrate to these new populations are looking for less crowded conditions with more resources. E) Gradually, the populations of ground squirrels will move from a clumped to a uniform population pattern of dispersion.
Answer: C
38) Owls eat rats, mice, shrews, and small birds. Assume that, over a period of time, an owl consumes 5,000 J of animal material. The owl loses 2,300 J in feces and owl pellets and uses 2,600 J for cellular respiration. What is the production efficiency of this owl? A) 0.02% B) 1% C) 4% D) 10% E) 40%
Answer: C
39) The success with which plants extend their range northward following glacial retreat is best determined by A) whether there is simultaneous migration of herbivores. B) their tolerance to shade. C) their seed dispersal rate. D) their size. E) their growth rate.
Answer: C
4) Extinction is a natural phenomenon. It is estimated that 99% of all species that ever lived are now extinct. Why then do we say that we are now experiencing an extinction (loss of biodiversity) crisis? A) Humans are ethically responsible for protecting endangered species. B) Scientists have finally identified most of the species on Earth and are thus able to quantify the number of species becoming extinct. C) The current rate of extinction is high and human activities threaten biodiversity at all levels. D) Humans have greater medical needs than at any other time in history, and many potential medicinal compounds are being lost as plant species become extinct. E) Most biodiversity hot spots have been destroyed by recent ecological disasters.
Answer: C
41) Which of the following is the best natural example of uniform distribution? A) bees collecting pollen in a wildflower meadow B) snails in an intertidal zone at low tide C) territorial songbirds in a mature forest during mating season D) mushrooms growing on the floor of an old-growth forest E) a cultivated cornfield in the Midwest
Answer: C
44) Why do some invertebrates, such as lobsters, show a "stair-step" survivorship curve? A) Many invertebrates mate and produce offspring on multiyear cycles. B) Within a species of invertebrates, younger individuals have a higher survivorship than older individuals. C) Many invertebrates molt in order to grow, and they are vulnerable to predation during their "soft shell" stage. D) Many invertebrate species have population cycles that go up and down according to the frequency of sunspots. E) The number of fertilized eggs that mature to become females in many species of invertebrates is based on ambient temperature.
Answer: C
45) Which island in Figure 41.4 would likely exhibit the most impoverished species diversity? A) A B) B C) C D) D E) E
Answer: C
49) In the nitrogen cycle, the bacteria that replenish the atmosphere with N2 are A) Rhizobium bacteria. B) nitrifying bacteria. C) denitrifying bacteria. D) methanogenic protozoans. E) nitrogen-fixing bacteria.
Answer: C
5) Photosynthetic organisms are unique to most ecosystems because they A) synthesize organic compounds they obtain from decaying heterotrophs. B) synthesize inorganic compounds from organic compounds. C) use light energy to synthesize organic compounds from inorganic compounds. D) use chemical energy to synthesize organic compounds. E) convert light energy into matter.
Answer: C
50) How does phosphorus normally enter ecosystems? A) cellular respiration B) photosynthesis C) rock weathering D) vulcanism E) atmospheric phosphorous gas
Answer: C
50) In 2008, the population of New Zealand was approximately 4,275,000 people. If the birth rate was 14 births for every 1,000 people, approximately how many births occurred in New Zealand in 2008? A) 6,000 B) 42,275 C) 60,000 D) 140,000 E) 600,000
Answer: C
50) What causes extremely high levels of toxic chemicals in fish-eating birds? A) depletion of ozone layer B) acid precipitation C) biological magnification D) greenhouse effect E) eutrophication
Answer: C
51) Consider two forests: one is an undisturbed old-growth forest, whereas the other has recently been logged. In which forest are species likely to experience exponential growth, and why? A) Old growth, because the stable conditions would favor exponential growth of all species in the forest. B) Old growth, because each of the species is well established and can produce many offspring. C) Logged, because the disturbed forest affords more resources for increased specific populations to grow. D) Logged, because the various populations are stimulated to a higher reproductive potential. E) Exponential growth is equally probable in old-growth and logged forests.
Answer: C
52) Why do logged tropical rain forest soils typically have nutrient-poor soils? A) Tropical bedrock contains little phosphorous. B) Logging results in soil temperatures that are lethal to nitrogen-fixing bacteria. C) Most of the nutrients in the ecosystem are removed in the harvested timber. D) The cation exchange capacity of the soil is reversed as a result of logging. E) Nutrients evaporate easily into the atmosphere in the post-logged forest.
Answer: C
53) Which of the following is most key to understanding the demographic transition in human population growth? A) education on global famine B) improved worldwide health care C) voluntary reduction of family size D) improved sanitary conditions in the world's hospitals E) reduction of casualties of war
Answer: C
54) Based on the intermediate disturbance hypothesis, a community's species diversity is increased by A) frequent massive disturbance. B) stable conditions with no disturbance. C) moderate levels of disturbance. D) human intervention to eliminate disturbance. E) intensive disturbance by humans.
Answer: C
54) Which statement is true with regard to human population growth? A) It is at a zero reproduction rate. B) Its rate of increase continues to grow at an exponential rate. C) Its rate of growth is slowing. D) Its rate of growth is increasing. E) There is no scientific prediction that can be made about human population growth.
Answer: C
55) The main goal of sustainable development is to 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.
Answer: C
57) Which of the following best illustrates the sustainable use of a resource? A) Coal mines in West Virginia remove the tops of mountains to extract large amounts of coal. B) Fishing industries improve their methods and now remove more than 90% of the fish in a region. C) Huge windmills in Texas are able to capture 50% of the wind energy in a specific region. D) Corporations are converting their company automobiles from gasoline to cheaper natural gas.
Answer: C
59) Which one of the following is the most sustainable source of energy? A) natural gas used to heat homes B) gasoline used to run cars C) hydroelectric dams D) a coal power plant
Answer: C
6) Although extinction is a natural process, current extinctions are of concern to environmentalists because A) more animals than ever before are going extinct. B) most current extinctions are caused by introduced species. C) the rate of extinction is higher than background extinction rates. D) current extinction is primarily affecting plant diversity. E) None of the options are correct.
Answer: C
62) Why were ecologists concerned about the shift in the peak caterpillar season from June 3, 1980, to May 15, 2000 in figure 43.2? A) The caterpillars would have eaten much of the foliage of the trees where flycatchers would have nested, rendering their nests more open to predation. B) The earlier hatching of caterpillars would compete with other insect larval forms that the flycatchers would also use to feed their young. C) The 2000 flycatcher nestlings would miss the peak caterpillar season and might not be as well fed, leading to population reductions. D) The flycatchers would have to migrate sooner to match their brood-rearing to the time of peak caterpillar season. E) Pesticides, which have a negative effect on the ecosystem, would have to be used to control the earlier outbreak of caterpillar hatching.
Answer: C
64) In which of the following situations would you expect to find the largest number of Kselected individuals? A) a recently abandoned agricultural field in Ohio B) a shifting sand dune community of south Lake Michigan C) an old-growth forest D) South Florida after a hurricane E) a newly emergent volcanic island
Answer: C
65)In the diagram of the nitrogen cycle in Figure 42.3, which number represents nitrite (NO2)? A) 1 B) 2 C) 3 D) 4
Answer: C
69) As big as it is, the ocean is nutrient-limited. If you wanted to investigate this, one reasonable approach would be to A) follow whale migrations in order to determine where most nutrients are located. B) observe Antarctic Ocean productivity from year to year to see if it changes. C) experimentally enrich some areas of the ocean and compare their productivity to that of untreated areas. D) compare nutrient concentrations between the photic zone and the benthic zone in various marine locations. E) contrast nutrient uptake by autotrophs in marine locations that are different temperatures.
Answer: C
70) Which climograph shows the climate for location 3 in Figure 40.1? A) B B) C C) D D) E E) F
Answer: C
17) Which of the following terms is used by ecologists to describe the community interaction where one organism makes the environment more suitable for another organism? A) parasitism B) mutualism C) inhibition D) facilitation E) commensalism
Answer: D
18) Which of these ecosystems accounts for the largest amount of Earth's net primary productivity? A) tundra B) savanna C) salt marsh D) open ocean E) tropical rain forest
Answer: D
71) Suppose you are studying the nitrogen cycling in a pond ecosystem over the course of a month. While you are collecting data, a flock of 100 Canada geese lands and spends the night during a fall migration. What could you do to eliminate error in your study as a result of this event? A) Find out how much nitrogen is consumed in plant material by a Canada goose over about a 12-hour period, multiply this number by 100, and add that amount to the total nitrogen in the ecosystem. B) Find out how much nitrogen is eliminated by a Canada goose over about a 12-hour period, multiply this number by 100, and subtract that amount from the total nitrogen in the ecosystem. C) Find out how much nitrogen is consumed and eliminated by a Canada goose over about a 12-hour period and multiply this number by 100 enter this +/- value into the nitrogen budget of the ecosystem. D) Do nothing. The Canada geese visitation to the lake would have negligible impact on the nitrogen budget of the pond. E) Put a net over the pond so that no more migrating flocks can land on the pond and alter the nitrogen balance of the pond.
Answer: C
72) Which of the following organisms is incorrectly paired with its trophic level? A) cyanobacterium—primary producer B) grasshopper—primary consumer C) zooplankton—primary producer D) eagle—tertiary consumer E) fungus—detritivore
Answer: C
73) Which of the following best substantiates why location 3 is an equatorial (tropical) climate in Figure 40.1? A) It has a monsoon season during the winter months. B) It has consistent monthly averages for rainfall. C) The temperature is high for each monthly average. D) The temperatures reach 100°F during some months. E) The temperatures are lower in June, July, and August.
Answer: C
74) Which zone has a condition of constant temperature in Figure 40.2? A) A B) B C) C D) D E) E
Answer: C
76) Which of the following has the greatest effect on the rate of chemical cycling in an ecosystem? A) the ecosystem's rate of primary production B) the production efficiency of the ecosystem's consumers C) the rate of decomposition in the ecosystem D) the trophic efficiency of the ecosystem E) the location of the nutrient reservoirs in the ecosystem
Answer: C
8) Which of the following is an example of Batesian mimicry? A) an insect that resembles a twig B) a butterfly that resembles a leaf C) a nonvenomous snake that looks like a venomous snake D) a fawn with fur coloring that camouflages it in the forest environment E) a snapping turtle that uses its tongue to mimic a worm, thus attracting fish
Answer: C
8) Why is the climate drier on the leeward side of mountain ranges that are subjected to prevailing winds? A) Deserts create dry conditions on the leeward side of mountain ranges. B) The sun illuminates the leeward side of mountain ranges at a more direct angle, converting to heat energy, which evaporates most of the water present. C) Pushed by the prevailing winds on the windward side, air is forced to rise, cool, condense, and drop its precipitation, leaving drier air to descend the leeward side. D) Air masses pushed by the prevailing winds are stopped by mountain ranges and the moisture is used up in the stagnant air masses on the leeward side. E) More organisms live on the sheltered, leeward side of mountain ranges where their utilization of water lowers the amount available when compared to the windward side.
Answer: C
9) What term did E. O. Wilson coin for our innate appreciation of wild environments and living organisms? A) bioremediation B) bioethics C) biophilia D) biophobia E) landscape ecology
Answer: C
90) If the direction of Earth's rotation reversed, the most predictable effect would be A) no more night and day. B) a big change in the length of the year. C) winds blowing from west to east along the equator. D) a loss of seasonal variation at high latitudes. E) the elimination of ocean currents.
Answer: C
In areas of permafrost, stands of black spruce are frequently observed in the landscape, whereas other tree species are noticeably absent. Often these stands are referred to as "drunken forests" because many of the black spruce are displaced from their normal vertical alignment. 85) What might be the adaptive significance of these unusual forests growing the way they do in this marginal habitat? A) Needles are adapted to withstand cold arctic temperatures. B) Branches are adapted to absorb more CO2 with this displaced alignment. C) Taproot formation is impossible, so trees developed shallow root beds and easily tilt. D) Trees are tilted so that snow won't break them or tip them over. E) Trees tip so that they do not compete with each other for sunlight.
Answer: C
The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, — denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 50) What interactions exist between a tick on a dog and the dog? A) +/+ B) +/o C) +/- D) o/o E) -/-
Answer: C
1) Which of the following statements is consistent with the principle of competitive exclusion? A) Bird species generally do not compete for nesting sites. B) The random distribution of one competing species will have a positive impact on the population growth of the other competing species. C) Two species with the same fundamental niche will exclude other competing species. D) Even a slight reproductive advantage will eventually lead to the elimination of the less well adapted of two competing species. E) Natural selection tends to increase competition between related species.
Answer: D
12) Which of the following is the most direct threat to biodiversity? A) increased levels of atmospheric carbon dioxide B) the depletion of the ozone layer C) overexploitation of selected species D) habitat destruction E) zoned reserves
Answer: D
13) According to most conservation biologists, the single greatest threat to global biodiversity is A) chemical pollution of water and air. B) stratospheric ozone depletion. C) overexploitation of certain species. D) alteration or destruction of the physical habitat. E) global climate change resulting from a variety of human activities.
Answer: D
13) In a typical grassland community, which of the following is the primary consumer? A) hawk B) snake C) shrew D) grasshopper E) grass
Answer: D
17) How might the extinction of some Pacific Island bats called "flying foxes" threaten the survival of over 75% of the tree species in those islands? A) wetland and riparian B) open and benthic ocean C) desert and high alpine D) taiga and second-growth forests E) tundra and arctic
Answer: D
19) Coral reefs can be found on the southeast coast of the United States but not at similar latitudes on the southwest coast. Differences in which of the following most likely account for this? A) sunlight intensity B) precipitation C) day length D) ocean currents E) salinity
Answer: D
19) Which of these ecosystems has the highest net primary productivity per square meter annually? A) savanna B) open ocean C) boreal forest D) tropical rain forest E) temperate forest
Answer: D
20) Which of the following examples poses the greatest potential threat to biodiversity? A) replanting, after a clear cut, a monoculture of Douglas fir trees on land that consisted of old-growth Douglas fir, western cedar, and western hemlock B) allowing previously used farmland to go fallow and begin to fill in with weeds and then shrubs and saplings C) trapping and relocating large predators, such as mountain lions, that pose a threat as they move into areas of relatively dense human populations D) importing an Asian insect into the United States to control a weed that competes with staple crops E) releasing sterilized rainbow trout to boost the sport fishing of a river system that contains native brook trout
Answer: D
20) Which of the following is a true statement regarding mineral nutrients in soils and their implication for primary productivity? A) Globally, phosphorous availability is most limiting to primary productivity. B) Adding a nonlimiting nutrient will stimulate primary productivity. C) Adding more of a limiting nutrient will increase primary productivity, indefinitely. D) Phosphorous is sometimes unavailable to producers due to leaching. E) Alkaline soils are more productive than acidic soils.
Answer: D
23) Which of the following conditions is the most likely indicator of a population in an extinction vortex? A) The population is geographically divided into many populations. B) The species in question is found only in small, stable pockets of its former range. C) The effective population size of the species falls below 500. D) Genetic measurements indicate a loss of genetic variation over time. E) The population is connected only by corridors.
Answer: D
24) Imagine that a deep temperate zone lake did not "turn over" during the spring and fall seasons. Based on the physical and biological properties of limnetic ecosystems, what would be the difference from normal seasonal turnover? A) The lake would be uniformly cold during the winter and summer. B) The lake would fail to freeze over in winter. C) An algal bloom would result every spring. D) The lake would suffer a nutrient depletion in its surface layers. E) The pH of the lake would become increasingly alkaline.
Answer: D
27) In a particular case of secondary succession, three species of wild grass all invaded a field. By the second season, a single species dominated the field. A possible factor in this secondary succession was A) equilibrium. B) facilitation. C) immigration. D) inhibition. E) parasitism.
Answer: D
29) How is it that satellites can detect differences in primary productivity on Earth? A) Photosynthetic organisms absorb more visible light in the 350-750 wavelengths. B) Satellite instruments can detect reflectance patterns of the photosynthetic organisms of different ecosystems. C) Sensitive satellite instruments can measure the amount of NADPH produced in the summative light reactions of different ecosystems. D) Satellites detect differences by comparing the wavelengths of light captured and reflected by photoautotrophs to the amount of light reaching different ecosystems. E) Satellites detect differences by measuring the amount of water vapor emitted by transpiring producers.
Answer: D
29) The long-term problem with red-cockaded woodpecker habitat intervention in the southeastern United States is A) the only habitat that can support their recovery is large tracts of mature oak forest. B) the mature pine forests in which they live cannot ever be subjected to forest fire. C) all of the appropriate red-cockaded woodpecker habitat has already been logged or converted to agricultural land. D) the social organization of the red-cockaded woodpecker precludes the dispersal of reproductive individuals. E) what habitat remains for the red-cockaded woodpecker does not contain trees suitable for nest-cavity construction.
Answer: D
31) Studying species transplants is a way that ecologists A) determine the abundance of a species in a specified area. B) determine the distribution of a species in a specified area. C) develop mathematical models for distribution and abundance of organisms. D) determine if dispersal is a key factor in limiting distribution of organisms. E) consolidate a landscape region into a single ecosystem.
Answer: D
32) Approximately how many kg of carnivore biomass can be supported by a field plot containing 1,000 kg of plant material? A) 10,000 B) 1,000 C) 100 D) 10 E) 1
Answer: D
32) Why do tropical communities tend to have greater species diversity than temperate or polar communities? A) They are less likely to be affected by human disturbance. B) There are fewer parasites to negatively affect the health of tropical communities. C) Tropical communities are low in altitude, whereas temperate and polar communities are high in altitude. D) Tropical communities are generally older than temperate and polar communities. E) More competitive dominant species have evolved in temperate and polar communities.
Answer: D
33) Which of the following is a correct statement about the McArthur/Wilson Island Equilibrium Model? A) The more species that inhabit an island, the lower the extinction rate. B) As the number of species on an island increases, the emigration rate decreases. C) Competitive exclusion is less likely on an island that has large numbers of species. D) Small islands receive few new immigrant species. E) Islands closer to the mainland have higher extinction rates.
Answer: D
34) Uniform spacing patterns in plants such as the creosote bush are most often associated with A) chance. B) patterns of high humidity. C) the random distribution of seeds. D) competitive interaction between individuals of the same population. E) the concentration of nutrients within the population's range.
Answer: D
37) Which of the following examples would most accurately measure the density of the population being studied? A) counting the number of prairie dog burrows per hectare B) counting the number of times a 1-kilometer transect is intersected by tracks of red squirrels after a snowfall C) counting the number of coyote droppings per hectare D) counting the number of moss plants in 1-m2 quadrats E) counting the number of zebras from airplane census observations.
Answer: D
37) Why is a pathogen generally more virulent in a new habitat? A) More pathogens tend to immigrate into newer habitats. B) Intermediate host species are more motile and transport pathogens to new areas. C) Pathogens evolve more efficient forms of reproduction in new environments. D) Hosts in new environments have not had a chance to become resistant to the pathogen through natural selection. E) New environments are almost always smaller in area, so that transmission of pathogens is easily accomplished between hosts.
Answer: D
40) Which of the following statements is a valid conclusion of this experiment in Figure 41.1? A) Balanus can survive only in the lower intertidal zone because it is unable to resist desiccation. B) Balanus is inferior to Chthamalus in competing for space on rocks lower in the intertidal zone. C) The two species of barnacles do not compete with each other because they feed at different times of day. D) The removal of Balanus shows that the realized niche of Chthamalus is smaller than its fundamental niche. E) These two species of barnacle do not show competitive exclusion. F) If Chthamalus were removed, Balanus's fundamental niche would become larger.
Answer: D
42) Which trophic level is most vulnerable to extinction? A) producer level B) primary consumer level C) secondary consumer level D) tertiary consumer level E) decomposer level
Answer: D
43) Which of the following best defines a cohort? A) a group of individuals that inhabits a small isolated region within the range for the species B) all of the individuals that are annually added to a population by birth and immigration C) the reproductive males and females within the population D) a group of the individuals from the same age group, from birth until they are all dead E) the number of individuals that annually die or emigrate out of a population
Answer: D
43) Which statement best describes what ultimately happens to the chemical energy that is not converted to new biomass in the process of energy transfer between trophic levels in an ecosystem? A) It is undigested and winds up in the feces and is not passed on to higher trophic levels. B) It is used by organisms to maintain their life processes through the reactions of cellular respiration. C) Heat produced by cellular respiration is used by heterotrophs to thermoregulate. D) It is eliminated as feces or is dissipated into space as heat in accordance with the second law of thermodynamics. E) It is recycled by decomposers to a form that is once again usable by primary producers.
Answer: D
45) What is 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% of the species present C) the maximum abundance level of a particular species, beyond which additional numbers will degrade a habitat D) the amount of added nutrient that can be absorbed by plants without damaging ecosystem integrity E) the number of predators an ecosystem can support that effectively culls prey populations to healthy levels
Answer: D
47) Starting from a single individual, what is the size of a population of bacteria that reproduce by binary fission every 20 minutes at the end of a 2-hour time period? (Assume unlimited resources and no mortality.) A) 8 B) 16 C) 32 D) 64 E) 128
Answer: D
48) Which of the following refers to the reflecting and absorption of infrared radiation by atmospheric methane, carbon dioxide, and water? A) depletion of ozone layer B) acid precipitation C) biological magnification D) greenhouse effect E) eutrophication
Answer: D
49) In July 2008, the United States had a population of approximately 302,000,000 people. How many Americans were there in July 2009, if the estimated 2008 growth rate was 0.88%? A) 2,700,000 B) 5,500,000 C) 303,000,000 D) 304,700,000 E) 2,710,800,000
Answer: D
5) Which of the following provides the best evidence of a biodiversity crisis? A) the incursion of a non-native species B) increasing pollution levels C) decrease in regional productivity D) high rate of extinction E) climate change
Answer: D
52) Logistic growth of a population is represented by dN/dt = A) rN/L B) rmax N C) rmax N (K + N) D) rmax N (K - N)/K E) rmax (N - K)/K N
Answer: D
55) Which of the following could qualify as a top-down control on a grassland community? A) limitation of plant biomass by rainfall amount B) influence of temperature on competition among plants C) influence of soil nutrients on the abundance of grasses versus wildflowers D) effect of grazing intensity by bison on plant species diversity E) effect of humidity on plant growth rates
Answer: D
56) Which of the following causes populations to shift most quickly from an exponential to a logistic population growth? A) increased birth rate B) removal of predators C) decreased death rate D) competition for resources E) favorable climatic conditions
Answer: D
56) Which of the following would be considered an example of bioremediation? A) using a bulldozer to reshape the land around an abandoned strip mine to change erosion patterns B) dredging a river bottom to remove contaminated sediments C) reconfiguring the channel of a river to increase the flow of water down a river D) raising chromium-accumulating plants to extract chromium from contaminated soil E) selectively harvesting younger trees in a forest to leave older trees for woodpecker nesting habitat
Answer: D
57) Often the growth cycle of one population has an effect on the cycle of another. As moose populations increase, for example, wolf populations also increase. Thus, if we are considering the logistic equation for the wolf population, dN/dt = rN , which of the factors accounts for the effect of the moose population? A) r B) N C) rN D) K E) dt
Answer: D
57) To selectively remove soil toxins from regions affected by Hurricane Katrina, some residents have raised sunflowers and other plants in their yards. Then, the mature plants are pulled up and safely stored with other contaminated wastes. This is an example of A) biological augmentation. B) reducing primary production. C) lowering production efficiency. D) bioremediation. E) arresting nutrient cycling.
Answer: D
61) The shift in the peak of caterpillar season in figure 43.2 is most likely due to A) pesticide use. B) earlier migration returns of flycatchers. C) an innate change in the biological clock of the caterpillars. D) global warming. E) acid precipitation in Europe.
Answer: D
63) If Figure 42.2 represents a terrestrial food web, the combined biomass of C + D would probably be A) greater than the biomass of A. B) less than the biomass of H. C) greater than the biomass of B. D) less than the biomass of A + B. E) less than the biomass of F.
Answer: D
65) One characteristic that distinguishes a population in an extinction vortex from most other populations is that A) its habitat is fragmented. B) it is a rare, top-level predator. C) its effective population size is much lower than its total population size. D) its genetic diversity is very low. E) it is not well adapted to edge conditions.
Answer: D
66) The main cause of the increase in the amount of CO2 in Earth's atmosphere over the past 150 years is A) increased worldwide primary production. B) increased worldwide standing crop. C) an increase in the amount of infrared radiation absorbed by the atmosphere. D) the burning of larger amounts of wood and fossil fuels. E) additional respiration by the rapidly growing human population.
Answer: D
66)In the diagram of the nitrogen cycle in Figure 42.3, which number represents the ammonium ion (NH4+)? A) 1 B) 2 C) 3 D) 4
Answer: D
69) Which climograph shows the climate for location 2 in Figure 40.1? A) B B) C C) D D) F E) H
Answer: D
71) Which climograph shows the climate for location 4 in Figure 40.1? A) A B) B C) C D) E E) G
Answer: D
74) The discipline that applies ecological principles to returning degraded ecosystems to a more natural state is known as A) population viability analysis. B) landscape ecology. C) conservation ecology. D) restoration ecology. E) resource conservation.
Answer: D
75) Nitrifying bacteria participate in the nitrogen cycle mainly by A) converting nitrogen gas to ammonia. B) releasing ammonium from organic compounds, thus returning it to the soil. C) converting ammonia to nitrogen gas, which returns to the atmosphere. D) converting ammonium to nitrate, which plants absorb. E) incorporating nitrogen into amino acids and organic compounds.
Answer: D
76) Which zone has the lowest biomass per unit of area in Figure 40.2? A) A B) B C) C D) D E) E
Answer: D
79) Which curve best describes survivorship in a marine crustacean that molts in Figure 40.3? A) A B) B C) C D) D E) E
Answer: D
86) Imagine that you are managing a large game ranch. You know from historical accounts that a species of deer used to live there, but they have been extirpated. You decide to reintroduce them. After doing some research to determine what might be an appropriately sized founding population, you do so. You then watch the population increase for several generations, and graph the number of individuals (vertical axis) against the number of generations (horizontal axis). The graph will likely appear as A) a diagonal line, getting higher with each generation. B) an "S" increasing with each generation. C) an upside-down "U" D) a "J" increasing with each generation. E) an "S" that ends with a vertical line.
Answer: D
10) We should care about loss in biodiversity in the populations of other species because of A) biophilia. B) potential loss of medicines and other products yet undiscovered from threatened species. C) potential loss of genes, some of which may code for proteins useful to humans. D) the risk to global ecological stability. E) All of the options are correct.
Answer: E
11) In mountainous areas of western North America, north-facing slopes would be expected to A) receive more sunlight than similar southern exposures. B) be warmer and drier than comparable southern-exposed slopes. C) consistently be steeper than southern exposures. D) support biological communities similar to those found at lower elevations on similar south- facing slopes. E) support biological communities similar to those found at higher elevations on similar south- facing slopes.
Answer: E
12) Which of the following would be most significant in understanding the structure of an ecological community? A) determining how many species are present overall B) determining which particular species are present C) determining the kinds of interactions that occur among organisms of different species D) determining the relative abundance of species E) all of the above
Answer: E
13) Which of the following studies would a community ecologist undertake to learn about competitive interactions? A) selectivity of nest sites among cavity-nesting songbirds B) the grass species preferred by grazing pronghorn antelope and bison C) nitrate and phosphate uptake by various hardwood forest tree species D) stomach analysis of brown trout and brook trout in streams where they coexist E) all of the above
Answer: E
14) Imagine some cosmic catastrophe jolts Earth so that its axis is perpendicular to the orbital plane between Earth and the sun. The most obvious effect of this change would be A) the elimination of tides. B) an increase in the length of night. C) an increase in the length of a year. D) a decrease in temperature at the equator. E) the elimination of seasonal variation.
Answer: E
15) Introduced species can have deleterious effects on biological communities by A) preying on native species. B) competing with native species for food or light. C) displacing native species. D) competing with native species for space or breeding/nesting habitat. E) All of the options are correct.
Answer: E
16) How might an ecologist test whether a species is occupying all of its fundamental niche or only a portion of it? A) Study the temperature range and humidity requirements of the species. B) Observe if the niche size changes after the addition of nutritional resources to the habitat. C) Observe if the niche size changes after the introduction of a similar non-native species. D) Measure the change in reproductive success when the species is subjected to environmental stress. E) Observe if the species expands its range after the removal of a competitor.
Answer: E
16) Which of the following environmental features might influence microclimates? A) forest canopy B) freshly plowed field C) log on the forest floor D) large boulder E) All of the options are correct.
Answer: E
20) What is the limiting factor for the growth of trees in the tundra? A) low precipitation B) lack of sunlight C) insufficient minerals in bedrock D) pH of soils E) permafrost
Answer: E
21) Which of the following is a type of research in which a conservation biologist would be involved? A) reestablishing whooping cranes in their former breeding grounds in North Dakota B) studying species diversity and interaction in the Florida Everglades, past and present C) studying the population ecology of grizzly bears in Yellowstone National Park D) determining the effects of hunting white-tailed deer in Vermont E) All of the options are correct.
Answer: E
25) If the sex ratio in a population is significantly different from 50:50, then which of the following will always be true? A) The population will enter the extinction vortex. B) The genetic variation in the population will increase over time. C) The genetic variation in the population will decrease over time. D) The effective population size will be greater than the actual population size. E) The effective population size will be less than the actual population size.
Answer: E
26) According to the nonequilibrium model, A) communities will remain in a climax state if there are no human disturbances. B) community structure remains stable in the absence of interspecific competition. C) communities are assemblages of closely linked species that are irreparably changed by disturbance. D) interspecific interactions induce changes in community composition over time. E) communities are constantly changing after being influenced by disturbances.
Answer: E
26) Which of the following life history traits can potentially influence effective population size (Ne)? A) maturation age B) genetic relatedness among individuals in a population C) population size D) gene flow between geographically separated populations E) All of the options are correct.
Answer: E
33) The amount of chemical energy in a consumer's food that is converted to its own new biomass during a given time period is known as which of the following? A) biomass B) standing crop C) biomagnification D) primary production E) secondary production
Answer: E
39) Why does a vegetarian leave a smaller ecological footprint than an omnivore? A) Fewer animals are slaughtered for human consumption. B) There is an excess of plant biomass in all terrestrial ecosystems. C) Vegetarians need to ingest less chemical energy than omnivores. D) Vegetarians require less protein than do omnivores. E) Eating meat is an inefficient way of acquiring photosynthetic productivity.
Answer: E
4) As you study two closely related predatory insect species, the two-spot and the three-spot avenger beetles, you notice that each species seeks prey at dawn in areas without the other species. However, where their ranges overlap, the two-spot avenger beetle hunts at night and the three-spot hunts in the morning. When you bring them into the laboratory and isolate the two different species, you discover that the offspring of both species are found to be nocturnal. You have discovered an example of A) mutualism. B) character displacement. C) Batesian mimicry. D) facultative commensalism. E) resource partitioning.
Answer: E
4) The growing season would generally be shortest in which of the following biomes? A) savanna B) temperate broadleaf forest C) temperate grassland D) tropical rain forest E) northern coniferous forest
Answer: E
41) Connell conducted this experiment (Figure 41.1) to learn more about A) character displacement in the color of barnacles. B) habitat preference in two different species of barnacles. C) desiccation resistance and barnacle species. D) how sea-level changes affect barnacle distribution. E) competitive exclusion and distribution of barnacle species.
Answer: E
41) Which of the following is primarily responsible for limiting the number of trophic levels in most ecosystems? A) Many primary and higher-order consumers are opportunistic feeders. B) Decomposers compete with higher-order consumers for nutrients and energy. C) Nutrient cycles involve both abiotic and biotic components of ecosystems. D) Nutrient cycling rates tend to be limited by decomposition. E) Energy transfer between trophic levels is almost always less than 20% efficient.
Answer: E
42) According to the Shannon Diversity Index, which block in Figure 41.2 would show the greatest diversity? A) 1 B) 2 C) 3 D) 4 E) 5
Answer: E
42) Which of the following choices would most likely promote random distribution? A) territorial species B) species that secrete chemicals to attract or inhibit other individuals C) flocking and schooling behaviors D) spacing during the breeding season E) homogeneous chemical and physical factors in the environment
Answer: E
43) Burning fossil fuels releases oxides of sulfur and nitrogen. These air pollutants can be responsible for A) the death of fish in lakes. B) precipitation with a pH as low as 3.0. C) calcium deficiency in soils. D) direct damage to plants by leaching nutrients from the leaves. E) All of the options are correct.
Answer: E
45) If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps involving humans, starting from phytoplankton to zooplankton to fish to seals to polar bears, then which of the following could be true? A) Polar bears can provide more food for humans than seals can. B) The total biomass of the fish is lower than that of the seals. C) Seal meat probably contains the highest concentrations of fat-soluble toxins. D) Seal populations are larger than fish populations. E) The fish can potentially provide more food for humans than the seal meat can.
Answer: E
46) Nitrogen is available to plants mostly in the form of A) N2 in the atmosphere. B) nitrite ions in the soil. C) uric acid from animal excretions. D) nucleic acids from decomposing plants and animals. E) nitrate and ammonium ions in the soil.
Answer: E
48) Which of the following locations is the reservoir for carbon in the carbon cycle? A) atmosphere B) sediments and sedimentary rocks C) fossilized plant and animal remains (coal, oil, and natural gas) D) plant and animal biomass E) all of the above
Answer: E
49) What is caused by excessive nutrient runoff into aquatic ecosystems? A) depletion of ozone layer B) acid precipitation C) biological magnification D) greenhouse effect E) eutrophication
Answer: E
5) Trees are not usually found in the tundra biome because of A) insufficient annual precipitation. B) acidic soils. C) extreme winter temperatures. D) overbrowsing by musk ox and caribou. E) permafrost
Answer: E
58) Natural selection involves energetic trade-offs between A) choosing how many offspring to produce over the course of a lifetime and how long to live. B) producing large numbers of gametes when employing internal fertilization versus fewer numbers of gametes when employing external fertilization. C) the emigration of individuals when they are no longer reproductively capable or committing suicide. D) increasing the number of individuals produced during each reproductive episode with a corresponding decrease in parental care. E) high survival rates of offspring and the cost of parental care.
Answer: E
6) Which of the following is an example of cryptic coloration? A) bands on a coral snake B) brown or gray color of tree bark C) markings of a viceroy butterfly's wings D) colors of an insect-pollinated flower's petals E) a "walking stick" insect that resembles a twig
Answer: E
60) Examine the food web for a particular terrestrial ecosystem in Figure 42.1. Which species is most likely a decomposer in this food web? A) A B) B C) C D) D E) E
Answer: E
60) Pacific salmon and annual plants are excellent examples of A) cohort disintegration. B) dispersion. C) the Allee effect. D) iteroparous reproduction. E) semelparous reproduction.
Answer: E
62) Examine the food web for a particular terrestrial ecosystem in Figure 42.1. Which pair of species could be omnivores? A) A and B B) A and D C) B and C D) C and D E) C and E
Answer: E
64) Your friend is wary of environmentalists' claims that global warming 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 increased over the past 150 years. B) Through measurements and observations, we know that CO2 levels and temperature fluctuations are directly correlated, even in prehistoric times. C) Global warming could have significant effects on agriculture in the United States. D) Sea levels will likely rise, displacing as much as 50% of the world's human population. E) All statements listed could be used.
Answer: E
67) What is the single greatest threat to biodiversity? A) overharvesting of commercially important species B) introduced species that compete with native species C) pollution of Earth's air, water, and soil D) disruption of trophic relationships as more and more prey species become extinct E) habitat alteration, fragmentation, and destruction
Answer: E
77) The Hubbard Brook watershed deforestation experiment yielded all of the following results except: A) Most minerals were recycled within a forest ecosystem. B) The flow of minerals out of a natural watershed was offset by minerals flowing in. C) Deforestation increased water runoff. D) The nitrate concentration in waters draining the deforested area became dangerously high. E) Calcium levels remained high in the soil of deforested areas.
Answer: E
77) Which curve best describes survivorship in marine molluscs in Figure 40.3? A) A B) B C) C D) D E) E
Answer: E
78) Which of the following would be considered an example of bioremediation? A) adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability B) using a bulldozer to regrade a strip mine C) dredging a river bottom to remove contaminated sediments D) reconfiguring the channel of a river E) adding seeds of a chromium-accumulating plant to soil contaminated by chromium
Answer: E
79) If you applied a fungicide to a cornfield, what would you expect to happen to the rate of decomposition and net ecosystem production (NEP)? A) Both decomposition rate and NEP would decrease. B) Both decomposition rate and NEP would increase. C) Neither would change. D) Decomposition rate would increase and NEP would decrease. E) Decomposition rate would decrease and NEP would increase.
Answer: E
81) Which statement best explains survivorship curve B in Figure 40.3? A) It is likely a species that provides little postnatal care, but lots of care for offspring during midlife, as indicated by increased survivorship. B) This curve is likely of a species that produces lots of offspring, only a few of which are expected to survive. C) It is likely a species where no individuals in the cohort die when they are at 60-70% relative age. D) There was a mass emigration of young to middle-aged individuals in this cohort. E) Survivorship can only decrease, therefore, this curve could not happen in nature
Answer: E
87) Which of the following biomes is correctly paired with the description of its climate? A) savanna-low temperature, precipitation uniform during the year B) tundra-long summers, mild winters C) temperate broadleaf forest-relatively short growing season, mild winters D) temperate grasslands-relatively warm winters, most rainfall in summer E) tropical forests-nearly constant day length and temperature
Answer: E
9) What would be the effect on climate in the temperate latitudes if Earth were to slow its rate of rotation from a 24-hour period of rotation to a 48-hour period of rotation? A) Seasons would be longer and more distinct (colder winters and warmer summers). B) There often would be a smaller range between daytime high and nighttime low temperatures. C) Large-scale weather events such as tornadoes and hurricanes would no longer be a part of regional climates. D) Winter seasons in both the northern and southern hemispheres would have more abundant and frequent precipitation events. E) There often would be a larger range between daytime high and nighttime low temperatures.
Answer: E
9) Which of the following is an example of an ecosystem? A) all of the brook trout in a 500-square- hectare river drainage system B) the plants, animals, and decomposers that inhabit an alpine meadow C) a pond and all of the plant and animal species that live in it D) the intricate interactions of the various plant and animal species on a savanna during a drought E) all of the organisms and their physical environment in a tropical rain forest
Answer: E
The symbols +, -, and o are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, — denotes a negative interaction, and o denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. 48) What interactions exist between a lion pride and a hyena pack? A) +/+ B) +/o C) +/- D) o/o E) -/-
Answer: E