AP Biology Ecology Multiple Choice Practice Test

1. Most organisms are dependent upon plants because A. they produce oxygen as a by-product of photosynthesis. B. they capture more energy than they consume. C. they function to prevent erosion and reduce desertification. D. they reduce the problems created by the greenhouse effect as they remove carbon dioxide from the atmosphere. E. their nutrients support a vast array of pollinators.

B. they capture more energy than they consume

28. Which of the following statements is NOT generally characteristic of parasites? A. They are specialists and usually are able to affect only one variety of hosts. B. They inflict serious injury and kill their hosts. C. Some reside inside their hosts, whereas others live outside their hosts. D. Their host may be a plant as well as an animal. E. Some require more than one host to complete the life cycle.

B. they inflict serious injury and kill their hosts.

34. The organisms that occupy the first trophic level near hydrothermal vents are A. detritivores. B. chemosynthetic bacteria. C. decomposers. D. photosynthetic bacteria. E. chemotrophic heterotrophs.

B.chemosynthetic bacteria

23. Arctic and alpine tundras have all of the following in common EXCEPT A. low moisture. B. permafrost. C. minimal plant life. D. cold temperatures. E. nutrient-poor soils.

B.permafrost

28. All of the following are considered water pollutants EXCEPT A. sewer effluents. B. runoff from undisturbed ecosystems. C. animal wastes. D. chemicals from factories. E. nutrients that promote algal blooms.

B.runoff from undisturbed ecosystems

15. Which of the following is NOT a common result of predation? A. The level of the predator population is maintained near or below the carrying capacity. B. Both predator and prey undergo selection leading to coevolution. C. The predator or prey becomes extinct. D. The level of the prey population is maintained near or below the carrying capacity of the environment. E. All of these are not common results.

C. the predator or prey becomes extinct

32. Which of the following statements is false about pioneer species? A. They have wide ranges of tolerance. B. Many are mutualistic with nitrogen-fixing bacteria. C. They remain permanent residents of the community. D. They include lichens and plants with short life cycles. E. They are often small annuals with an abundance of easily dispersed seeds.

C. they remain permanent residents of the community

16. Ladybugs are effective natural control agents against pest insects, but as gardeners soon find out, ladybugs do not reduce pest populations to zero because A. they can't fly to find pests on nearby plants. B. of their very selective feeding habits. C. to do so jeopardizes their own existence. D. they don't live long enough. E. their reproductive capacity is nonexistent.

C. to do so jeopardizes their own existence

16. N is equal to the initial carrying capacity at A. A. B. B. C. C. D. D. E. E.

D. D.

8. Which of the following is NOT true for a population growing exponentially? A. The number of individuals added to the population in a year is greater than it was the previous year. B. The population growth rate increases year after year. C. Its r remains constant in the short-run. D. The doubling time remains constant. E. All of these are NOT true.

D. The doubling time remains constant

4. The relationship above is A. a parasitic association. B. predation. C. resource partitioning. D. a mutualistic association essential to the fish but not the anemone. E. none of these.

D. a mutualistic association essential to the fish but not the anemone

13. Which of the following is(are) true about predator-prey coevolution? A. Each species exerts selection pressure on the other. B. Predators are selective agents that favor improved prey defenses. C. Prey with better defenses are selective agents that favor better predator hunting skills. D. All of the above are true. E. None of the above are true.

D. all of the above are true

9. Competitive exclusion is based on the idea that A. one species will hold some sort of advantage over the other one. B. no two species can completely occupy the same niche. C. the more two species overlap in their capacity to obtain and use resources the less likely they are to coexist. D. all of these are true. E. none of these are true.

D. all of these are true

32. All of the following are true regarding coral reefs EXCEPT that they A. develop in warm, clear waters near coasts or volcanic islands. B. are found between 25 degrees north and south. C. are wave-resistant formations. D. are areas of abundant resources and minimal competition among inhabitants. E. contain the remains of hard corals and the mineral-hardened cell walls of red algae.

D. are areas of abundant resources and minimal competition among inhabitants

10. Populations A. are only limited by one factor at a time. B. increase arithmetically. C. may increase indefinitely. D. are limited by the carrying capacity. E. overcome limiting factors by increasing their biotic potential.

D. are limited by the carrying capacity

13. The release of DDT into the environment to control some insect pests results in the highest detectable concentrations A. at the beginning of the food chain. B. in the targeted insect pest. C. close by rivers and lakes. D. at the top of the food chain. E. in the targeted ecosystem.

D. at the top of the food chain

20. A significant fraction of the earth's carbon is found in all EXCEPT which of the following forms? A. carbonate B. carbon dioxide C. cellulose D. carbon monoxide E. dissolved in seawater

D. carbon monoxide

20. What conclusion can be drawn from research on abundance cycles of Canadian lynx and snowshoe hare? A. A simple predator-prey model explains the results. B. A simple plant-herbivore model explains the results. C. Raptor activity has no effect on the outcome. D. Complex variables are involved. E. Manipulation of experimental plots stopped cyclic changes in population densities.

D. complex variables are involved

18. Which of the following is the correct sequence in terms of increasing size? A. ecosystem >>> biogeographic realm >>>biome >>>biosphere B. ecosystem >>> biome >>> biosphere >>>biogeographic realm C. biome >>> ecosystem >>> biogeographic realm >>>biosphere D. ecosystem >>> biome >>> biogeographic realm >>>biosphere E. biogeographic realm >>> biome >>> ecosystem >>>biosphere

D. ecosystem- biome- biogeographic realm- biosphere

8. In most cases of interspecific interference competition, the inferior competitor displaced from an area of niche overlap is A. smaller. B. slower. C. more specialized in its niche requirements. D. less specialized in its niche requirements. E. taxonomically distant.

D. less specialized in its niche requirements

17. Which of the following is true regarding the hydrologic cycle? Most of the water that evaporates from the oceans A. remains in the atmosphere. B. is transported over land. C. precipitates onto land. D. precipitates onto the oceans. E. ends up as groundwater.

D. precipitates onto the oceans

14. Humans hunt the black rhinoceros, which is rapidly approaching extinction as a result of this predation. What accounts for the absence of stable coexistence between the two species? A. Predator and prey have not coevolved. B. Human predation is not necessarily density-dependent. C. The prey reproductive rate is greater than that of the predator. D. Predator and prey have not coevolved, and human predation is not necessarily density-dependent. E. Predator and prey have not coevolved, human predation is not necessarily density-dependent, and the prey reproductive rate is greater than that of the predator.

D. predator and prey have not coevolved and human predation is not necessarily density-dependent.

9. Which of the following represents energy flow in a grazing food web? A. producers >>> detritivores >>> decomposers B. producers >>> decomposers >>> detritivores C. producers >>> herbivores >>> decomposers >>> carnivores D. producers >>> herbivores >>> carnivores >>> decomposers E. producers >>> herbivores >>> detritivores >>> carnivores

D. producers- herbivores- carnivores- decomposers

11. The fact that all three species survive in the same habitat is due to A. resource partitioning. B. overlapping but nonidentical niches. C. interference competition. D. resource partitioning and overlapping but nonidentical niches. E. resource partitioning, overlapping but nonidentical niches, and interference competition.

D. resource partitioning and overlapping but nonidentical niches

35. In 1882, the tropical volcanic island Krakatoa exploded and was reduced to an abiotic island covered by a thick layer of volcanic ash. By 1933, populations of all of the following organisms were present. Which population was probably established after the others? A. ferns B. bacteria C. insects D. rodents E. mosses

D. rodents

7. A third level consumer may eat A. herbivores. B. primary producers. C. primary carnivores. D. second trophic level organisms. E. none of these.

D. second trophic level organisms.

34. The plants and animals now present on acreage from which the trees were removed ten years earlier represent A. primary succession. B. a climax forest. C. pioneer species. D. secondary succession. E. species introductions.

D. secondary succession

33. Which of the following statements about ecological succession is false? A. A disturbed area within a community may recover quickly if improved soil remains. B. Pioneer species are the start of community structure. C. The wastes and remains of early colonizers favor the survival of new species. D. Secondary succession occurs on a new volcanic island. E. Later successional species outcompete earlier species.

D. secondary succession occurs on a new volcanic island

18. Most of the annual cycling of carbon takes place between A. groundwater and surface freshwater systems. B. the atmosphere and the land. C. the land and surface freshwater systems. D. the oceans and the atmosphere. E. the oceans and the land.

D. the oceans and the atmosphere

19. Carbon is introduced into the atmosphere by all EXCEPT which of the following means? A. respiration B. volcanic eruptions C. burning of fossil fuels D. wind erosion of rocks E. combustion of wood

D.wind erosion of rocks

1. Which of the following is NOT true regarding factors that affect the dispersion of organisms in nature? A. Most environmental resources are randomly distributed. B. Biological conditions tend to be non-uniform. C. Dispersal of offspring is often limited or controlled by environmental factors. D. The development of societies in some populations controls distribution. E. Every species is adapted to specific environmental conditions.

A. Most environmental resources are randomly distributed.

39. Many introduced species have deleterious effects on communities and ecosystems because A. coevolved parasites and competitors are absent. B. the introduced species are long-lived. C. predators prefer the introduced species; therefore, the local prey proliferate to dangerously high levels. D. the communities from which they came lost an important predator, competitor, or parasite. E. all of these occur.

A. coevolved parasites and competitors are absent

12. In contrast to a predator, a parasite usually A. does not kill the animal on which or in which it lives. B. kills its host. C. is a short-term visitor. D. is larger than its host. E. does not kill the animal on which or in which it lives and is larger than its host.

A. does not kill the animal on which or in which it lives

36. The poor fishing off the coast of Peru associated with El Niño is related to oceanic A. downwellings. B. upwellings. C. thermal inversions. D. cyclonic activity. E. oxygen depletion.

A. downwellings

38. The above graph demonstrates A. how periwinkle population density can act to stabilize a community. B. how diversity of algal groups peaks when the periwinkle population goes down. C. as periwinkle populations increase, algal diversity remains constant. D. the rate of the tide is the strongest influence on the population of algae. E. all of these.

A. how periwinkle population density can act to stabilize a community

43. Graph B shows that breeding bird species richness A. is greater than 1,000 at the equator. B. drops off in northern and southern latitudes. C. is less than that of ants at 30 degrees north latitude. D. drops by more than an order of magnitude at 40 degrees north latitude. E. includes all of these.

A. is greater than 1,000 at the equator

23. Hover flies like to drop in at outdoor picnics to sample the sweets, but the reaction of the humans is to flee the scene because of the flies' uncanny resemblance to bees. Thus, the survival of the hover fly is enhanced by A. mimicry. B. display behavior. C. warning coloration. D. chemical defenses. E. camouflage.

A. mimicry

26. The images above are an example of A. mimicry. B. display behavior. C. warning coloration. D. chemical defenses. E. camouflage.

A. mimicry

18. Predators capture a constant proportion of prey without regard to prey abundance as is shown in A. model I. B. model II. C. model III. D. models II and III. E. all of these models.

A. model l

29. Which of the following elements released in compound form can cause conditions that lead to an exhaustion of oxygen from aquatic ecosystems? A. phosphorus B. sulfur C. calcium D. zinc E. nitrogen

A. phosphorus

20. In shrublands A. plants are adapted to episodes of fire. B. primary production is abundant throughout the year. C. there are constant cool temperatures throughout the year. D. winters are mild and summers are wet. E. precipitation occurs evenly year round.

A. plants are adapted to episodes of fire.

2. Which of the following combinations of organisms can survive in isolation from other forms of life? A. producers and decomposers B. producers and carnivores C. carnivores and decomposers D. carnivores and parasites E. producers and parasites

A. producers and decomposers

10. Which one of the following is the final consequence of one or more of the others? A. resource partitioning B. competition C. predation D. parasitism E. parasitoidism

A. resource partitioning

10. Which of the following statements is false? A. Heat loss represents a one-way loss of energy from an ecosystem. B. Consumers use only a portion of the energy contained in the food that they eat. C. In some ecosystems, the majority of the energy stored in plants does not become available until the plants die. D. Heat and energy are lost by each organism in the ecosystem. E. Grazing food webs are more energy efficient than detrital food webs.

E. Grazing food webs are more energy efficient than detrital food webs.

6. Which of the following is NOT true regarding biotic potential? It A. varies from one species to another. B. is related to the timing of the first reproduction. C. is related to the frequency of reproduction. D. is related to the number of offspring produced. E. increases as population density increases.

E. Increases as population density increases

5. If K (carrying capacity) for a population is 1,200, and r =0.1, which of the following populations will show the greatest increase over the course of one year assuming exponential growth? A. N = 100 B. N = 200 C. N = 300 D. N = 700 E. N = 900

E. N= 900

4. The accuracy of the capture-recapture methods depends on all of the following EXCEPT that A. marked individuals are recaptured at random. B. unmarked individuals are captured at random. C. none of the marked individuals are overlooked. D. no marked individual dies or departs during the study. E. no new individuals are produced during the study.

E. No new individuals are produced during the study.

36. According to the intermediate disturbance hypothesis, A. species richness becomes greatest in between disturbances of moderate intensity or frequency. B. a disturbance is necessary during succession in order to stabilize the community. C. community succession is highly predictable. D. competition and other species interactions are the most important factors in shaping community structure. E. a community reverts to a climax state after a disturbance.

A. species richness becomes greatest in between disturbances of moderate intensity or frequency

24. Eutrophication is A. the enrichment of a body of water with nutrients. B. the acidification of a body of water with leaves of a hardwood tree. C. the turning of water during winter months in lakes. D. the algal production of toxins to kill fish. E. none of these.

A. the enrichment of a body of water with nutrients

2. Which of the following provides a chicken rancher using a free-roaming arrangement for his flock the data necessary to ensure maximum survival of his hens? A. distribution of chickens throughout the range B. total number of chickens C. chickens per square foot of the range D. total square footage of the range E. crude density of the chicken population

A.Distribution of chickens throughout the range

35. Upwelling A. increases productivity by bringing nutrient-rich cool water to the surface of the ocean. B. occurs in cold northern oceans. C. refers to the accumulation of pollution in the North Pacific Ocean. D. occurs when warm ocean currents approach the edge of continents. E. generates the major climatic changes in the Pacific Ocean known as El Niño.

A.increases productivity by bringing nutrient-rich cool water to the surface of the ocean

26. Which of the following is(are) responsible for the movement of minerals upstream? A. migratory fish and other animals B. phytoplankton C. bacteria D. leaching E. all of these

A.migratory fish and other animals

30. Primary treatment of sewage involves mostly A. the physical treatment of wastewater through filtration and sedimentation. B. the biological degradation of the organic material. C. the detoxification of heavy metals. D. altering the pH of the wastewater to kill bacteria. E. all of these.

A.the physical treatment of wastewater through filtration and sedimentation

9. Which of the following statements is NOT true regarding population-limiting factors? A. The number of limiting factors may be extensive. B. A combination of limiting factors is required to inhibit population growth. C. Rapidly growing populations are affected by limiting factors. D. Small populations are affected by limiting factors. E. Slow-growing populations are affected by limiting factors.

B. A combination of limiting factors may be extensive

14. The effect of population growth limiting factors begin to become evident at about A. A. B. B. C. C. D. D. E. E.

B. B.

6. In exploitive competition, A. one species blocks access of another species to resources. B. both species have access to a resource. C. both species are equally good at utilizing the resource. D. all of these occur. E. none of these occur.

B. both species are equally good at utilizing the resource

29. All of the following are desirable attributes of an effective parasitoid control agent EXCEPT A. being well adapted to the host. B. having limited search capability. C. having a high reproductive rate. D. being mobile. E. being capable of quick responses to host population change.

B. having limited search capability

30. Actual physical contact between interactants does not necessarily occur A. between parasitoid and prey. B. in social parasitism. C. in a predator-prey reaction. D. when a parasite feeds on a host. E. in any of these.

B. in social parasitism

17. The ability of predators to eat and digest prey determines the number of prey captured as is shown in A. model I. B. model II. C. model III. D. models I and II. E. none of these models.

B. model ll

5. Primary carnivores are A. tertiary consumers in the second trophic level. B. secondary consumers in the third trophic level. C. secondary consumers in the second trophic level. D. tertiary consumers in the fourth trophic level. E. secondary consumers in the first trophic level.

B. secondary consumers in the third trophic level

41. Which of the following is(are) NOT a factor(s) that explain(s) the area effect on island diversity? A. Larger islands have more habitats. B. Smaller islands have more varied and higher elevations. C. Larger islands intercept more colonizers. D. Smaller islands have less complex topography. E. All of these are not factors.

B. smaller islands have more varied and higher elevations

8. Food chains in the ocean depths tend to be long because these habitats have A. an abundance of producers. B. stable environmental conditions. C. a variety of energy sources. D. an abundance of decomposers. E. small numbers of predators.

B. stable environmental conditions

1. In facultative mutualism A. both species are animals. B. the interaction is helpful but not essential for survival. C. one species is an animal and the other a fungus. D. each species must have access to the other to complete its life cycle. E. none of these is true.

B. the interaction is helpful but not essential for survival

31. During the process of community succession, according to the traditional view, A. the total biomass remains constant. B. there are increasing possibilities for resource partitioning. C. the pioneer community gives way quickly to the climax community, followed by a succession of more diverse arrays of organisms. D. nutrients cycle more rapidly with time. E. all of these occur.

B. there are increasing possibilities for resource partitioning

7. If a population has an r = 0.02, which of the following statements must be true? A. Two of every 100 individuals will give birth over the course of a year. B. Two individuals will be born for every 100 individuals in the population over the course of a year. C. Births will exceed deaths by 2 percent over the course of a year. D. The number of individuals added to the population will be 2 percent greater than the number of individuals removed from the population over the course of a year. E. None of these are true.

E. None of these are true

17. The population is in exponential growth at A. A. B. B. C. C. D. D. E. E.

A. A.

16. Which of the following statements is false? A. Ecologists use models to represent relationships between biogeochemical cycles and most ecosystems. B. The physical environment has virtually no reservoirs for most elements. C. Inputs from the physical environment and recycling made possible by decomposers and detritivores maintain the nutrient reserves in an ecosystem. D. In most major ecosystems, the amount of nutrients that is cycled within the ecosystem is greater than the amount entering or leaving the ecosystem in a given year. E. Once elements are in the biological parts of the biogeochemical cycles, they are unlikely to leave until the organism dies.

B.the physical environment has virtually no reservoirs for most elements

3. Which of the following is NOT true regarding population counts? A. A full population count is usually impractical. B. Ecologists estimate a population's total density from a sample of the population. C. Sampling within quadrats is particularly useful for most populations of migrating animals. D. A full population count is possible for large animals in small areas. E. Capture-recapture methods are used to estimate the population's size of species that do not "stay put.

C. Sampling within quadrats is particularly useful for most populations of migrating animals.

25. Eutrophication is associated with all of the following characteristics of a lake EXCEPT A. decrease in depth. B. limited transparency. C. abundant oxygen at all levels. D. increased abundance of anaerobic decomposers. E. abundant phytoplankton.

C. abundant oxygen at all levels.

22. In fireflies, females attract males of the same species by means of a species-specific flashing pattern. Females of the genus Photuris are capable of producing flashing patterns that resemble those produced by fireflies of the genus Photinus. When a Photinus male approaches a Photuris female, she kills and eats him. This is an example of A. chemical defenses. B. parasitism. C. aggressive mimicry. D. commensalism. E. moment-of-truth defenses.

C. aggressive mimicry

2. Which of the following associations is NOT an example of obligatory mutualism? A. mycorrhiza and plant roots B. yucca plants and yucca moths C. ants and aphids D. lichens E. all of these

C. ants and aphids

12. Most of the energy within an ecosystem is lost A. when organisms disperse. B. when organisms die. C. as a result of metabolism. D. by organisms at the top of the food web. E. as a result of decomposition.

C. as a result of metabolism

13. A J-shaped population growth curve becomes an S-shaped one A. as more resources become available. B. if the data are plotted on semi-log graph paper. C. as the carrying capacity is reached. D. if reproduction stops. E. if any of these occur.

C. as the carrying capacity is reached

14. Long-lasting pesticides such as DDT A. are target-specific. B. are the most effective control over pests. C. build up in concentration as they pass up a food chain. D. break down after the organism that receives the pesticide dies. E. do all of these.

C. build up in concentration as they pass up a food chain

3. Which of the following is NOT true of ecosystems? A. Although they may include many different species, many features of ecosystem structure and function are alike. B. Autotrophs secure energy and nutrients that are then used by heterotrophs. C. Energy cycles and minerals flow through ecosystems. D. Many different food chains are represented in most ecosystems. E. Ecosystems are characterized by relatively few trophic levels.

C. energy cycles and minerals flow through ecosystems

11. Gross primary productivity refers to the total A. quantity of solar energy available to the ecosystem in a given period of time. B. quantity of solar energy reaching a given area of the ecosystem. C. energy trapped initially by the producers. D. energy used by the heterotrophs of the ecosystem in a given period of time. E. energy used by the producers for their growth and reproduction.

C. energy trapped initially by the producers

21. Which of the following biomes supports and is characterized by the greatest number and diversity of herbivores? A. tundra B. taiga C. grassland D. chaparral E. desert

C. grassland

5. The image in the above photograph is a prime example of A. double mutualism. B. associative commensalism. C. interference competition. D. team predation. E. parasitism.

C. interference competition

7. An aggressive species of chipmunks keeps other chipmunk species out of its habitat. This behavior provides an example of A. a neutral interaction. B. exploitation competition. C. interference competition. D. competitive exclusion. E. intraspecific competition.

C. interference competition

11. The animal in the above photograph was adversely affected by ____ and is making a comeback thanks to____. A. global cooling; heat producing chemical added to their diet B. sexually transmitted viruses; a new vaccine C. limited number of natural cavities; artificial nesting boxes D. high incidence of males being born; transplantation of females from other areas E. all of these

C. limited number of natural cavities; artificial nesting

19. Predators can switch to alternative prey when a prey species is low in abundance as is shown in A. model I. B. model II. C. model III. D. models I and III. E. all of these models.

C. model lll

19. Which of the following factors is most important in determining the type of biomes found in a particular region? A. soil type B. light intensity C. temperature D. type of animals in the region E. wind patterns

C. temperature

40. Species richness refers specifically to A. the numbers of individuals of each species present. B. the ability of larger animals to enrich themselves by successfully preying on smaller ones. C. the number of different species in the habitat. D. the feeding levels at which the animals are located. E. none of these.

C. the number of different species in the habitat

27. Which of the following statements about parasites is true? A. Parasites usually do not kill their hosts. B. The parasite species that infects a particular host species becomes less virulent over evolutionary time. C. Death may occur when a parasite attacks a novel host. D. Parasites usually do not kill their hosts, and the parasite species that infects a particular host species becomes less virulent over evolutionary time. E. Parasites usually do not kill their hosts; the parasite species that infects a particular host species becomes less virulent over evolutionary time, and death may occur when a parasite attacks a novel host.

E. Parasites usually do not kill their hosts; the parasite species that infects a particular host species becomes less virulent over evolutionary time, and death may occur when a parasite attacks a novel host.

15. Ecosystems obtain essential raw materials from A. the components of water molecules. B. mineral ions dissolved in water. C. the weathering of rocks. D. the atmosphere. E. all of these.

E. all of these

25. Parasites impact host populations by A. draining nutrients from hosts. B. making hosts more vulnerable to predation. C. lowering birth rates and raising death rates. D. affecting intraspecific and interspecific competition. E. all of these.

E. all of these

4. The primary consumer is A. the second link in a food chain. B. an herbivore. C. an animal. D. eaten by a carnivore. E. all of these.

E. all of these

3. In mycorrhizal associations A. fungal hyphae penetrate plant root cells or form mats around them. B. the plant takes some minerals from the fungus. C. the fungus takes some sugars from the plant. D. the fungus depends upon the plant for its reproductive success. E. all of these are true.

E. all of these are true

6. A secondary carnivore may eat A. herbivores. B. primary producers. C. primary carnivores. D. second trophic level consumers. E. any of these.

E. any of these

24. The animal in the above figure is using ____ for protection. A. mimicry B. display behavior C. warning coloration D. chemical defenses E. camouflage

E. camouflage

37. Species interactions may A. stabilize a community. B. cause competitive exclusion. C. promote community diversity. D. result in species extinctions. E. do all of these.

E. do all of these

12. Limiting factors A. produce more pronounced effects as a population grows. B. prevent indefinite, exponential population growth. C. can be either density-dependent or density-independent. D. acting together constitute environmental resistance to population growth. E. include all of these.

E. include all of these

33. Reef systems A. are wave resistant formations. B. are formed from calcium carbonate secreted by coral polyps. C. have symbiotic dinoflagellates in the living coral. D. have shown widespread bleaching; death of corals is being reported worldwide. E. include all of these.

E. include all of these

42. Graph A shows that ant species richness A. peaks at the equator. B. drops by 50 percent at 30 degrees north latitude. C. is less than 50 at 60 degrees north latitude. D. is somewhat greater at 30 degrees north latitude than at 30 degrees south latitude. E. includes all of these.

E. includes all of these

21. Which of the following statements about predation is(are) true? A. It can result in an increase in species diversity. B. It can cause extinction of a prey species. C. It can prevent extinction of a prey species. D. It can result in an increase in species diversity, and it can cause extinction of a prey species. E. It can result in an increase in species diversity, it can cause extinction of a prey species, and it can prevent extinction of a prey species.

E. it can result in an increase in species diversity, it can cause extinction of a prey species, and it can prevent extinction of a prey species

44. There are more insect species per square kilometer in a Brazilian rainforest than there are in a redwood forest of the Pacific Northwest of the United States. An explanation for this finding is that A. the tropics have been climatically stable for a longer period of time than have temperate areas. B. species richness may be self-reinforcing. C. tropical communities have been evolving for a longer time than temperate ones. D. the tropics have been climatically stable for a longer period of time than have temperate areas, and species richness may be self-reinforcing. E. the tropics have been climatically stable for a longer period of time than have temperate areas, species richness may be self-reinforcing, and tropical communities have been evolving for a longer time than temperate ones.

E. the tropics have been climatically stable for a longer period of time than have temperate areas, species richness may be self-reinforcing, and tropical communities have been evolving for a longer time than temperate ones.

15. A change in the environment's long-term ability to sustain the population is indicated by A. A. B. B. C. C. D. D. E. E.

E.E.

27. Which of the following affects the composition of river water? A. human activity B. mudslides C. nutrients from leaves falling into the river D. debris from fires E. all of these

E.all of these

31. Net primary productivity of a mangrove wetland depends on A. salinity. B. nutrient availability. C. tidal volume. D. tidal flow rate. E. all of these.

E.all of these

22. The removal of trees from tropical rain forests for the purpose of large-scale food crop agriculture is not recommended because rain forests A. are poor in organic nutrients. B. are poor in minerals. C. have a very poor nutrient reservoir. D. have soils that are highly weathered. E. include all of these.

E.include all of these