Chapter 53

5) Detritus can be consumed by which of the following primary decomposers? I. bacteria II. archaea III. fungi IV. earthworms A) only I and II B) only II and IV C) only I, II, and IV D) only II, III, and IV E) only I, II, III, and IV

E

51) In the accompanying figure, which of these countrices has the highest per capita CO2 emissions? A) China B) Canada C) Japan D) Germany E) Australia

E

17) 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.

A

22) Consider the food chain of grass - grasshopper - mouse - snake - hawk. About how much of the chemical energy fixed by photosynthesis of the grass (100 percent) is available to the hawk? A) 0.01 percent B) 0.1 percent C) I percent D) 10 percent E) 60 percent

A

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

A

26) The accompanying figure represents net primary productivity organized by A) biome B) geography C) region D) continent

A

3) Which of the following consume other living organisms? I. primary producers II. herbivores III. carnivores IV. decomposers A) only II and III B) only I and IV C) only I, II, and IV D) only II, III, and IV E) only I, II, and III

A

32) Which of the following most often controls the rate of nutrient cycling in ecosystems? A) rate of decomposition of detritus B) primary productivity C) secondary productivity D) both primary and secondary productivity

A

38) Consider the global nitrogen cycle depicted in the accompanying figure. How are humans altering this cycle? A) industrial nitrogen fixation B) nitrogen lost to the atmosphere C) reduction of nitrogen available to terrestrial ecosystems D) reduction of nitrogen fixation by bacteria E) permanent burial of nitrogen in coastal environments through runoff

A

42) Which of the following locations is the main reservoir for nitrogen in the 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

A

52) In the accompanying figure, which of these countries has the highest total CO2 emissions? A) China B) Canada C) Japan D) Germany E) Australia

A

54) Using the accompanying figure, what is the predicted change in temperature under a model with continued very high emission of greenhouse gases? A) 7°C B) 1°C C) -4°C D) 3°C E) 0°C

A

8) Why is energy lost when herbivores eat primary producers? A) Energy is lost because most of the total energy consumed is used for cellular respiration rather than growth and reproduction B) Primary producers cannot produce once eaten. C) Digestion takes place so rapidly that very little energy is absorbed. D) Most primary producers contain no usable energy for herbivores.

A

12) Which letter represents an organism that could be a producer? A) A B) B C) C D) D E) E

B

18) 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 percent in most ecosystems

B

19) 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 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

B

2) Approximately what percentage of the energy from sunlight is converted into gross primary production? A) 10 percent B) 0.8 percent C) 25 percent D) 100 percent E) 5 percent

B

27) Which habitat types in the accompanying figure cover the largest area? A) tropical wet forest plus the ocean neritic zone B) open ocean C) algal beds and reefs plus the ocean neritic zone D) wetlands plus the ocean neritic zone

B

28) Which habitat type in the figure makes available the most new tissue to consumers? A) tropical wet forest B) open ocean C) algal beds and reefs D) wetlands

B

30) Considering its total area covered, which ecosystem type represented in the figure has a very low level of economic impact on Earth's ecosystem, assuming that NPP is positively correlated with economic value? A) tropical wet forest B) rock, sand, and ice C) tropical seasonal forest D) ocean neritic zone

B

33) After looking at the experiment in the accompanying figure, what can be said about nutrient export in ecosystems? Nutrient export is A) typically 10 times lower in a clear-cut watershed B) typically 10 times higher in a clear-cut watershed C) typically 10 times higher in an uncut watershed D) not affected by any form of cutting

B

4) Which of the following factors account for the inefficiency of the rate of photosynthesis? I. Even when conditions are ideal, the pigments that drive photosynthesis can absorb only a fraction of the light wavelengths available and thus s a a fraction of the total energy received. II. Plants in equatorial biomes have drastically reduced photosynthetic rates in winter. III. If conditions get dry, stomata close to conserve water. IV. The efficiency of enzymes is not temperature dependent. A) only II and III B) only I and III C) only I, II, and IV D) only II, III, and IV E) only I, II, and III

B

44) Considering the global carbon cycle, which of the following is the largest reservoir of carbon? A) terrestrial ecosystems B) occans C) atmosphere D) algae in lakes and streams

B

50) Which of the following are TRUE about the greenhouse effect? I. High-energy solar radiation enters the atmosphere. II. Some of the energy is reflected, and some is absorbed by the Earth's surface. III. Heat is emitted as infrared radiation, and some of it is retained in the atmosphere, decreasing the temperature on Earth. A)I B) I and II C) I, II, and III D) II

B

55) Using the accompanying figure, what is the predicted change in temperature under a model with dramatic reduction of greenhouse gases? A) 7°C B) <1°C C) -4°C D) 3°C E) 0°C

B

57) Which of the following are negative biological consequences of climate change? I. changes in geographic ranges II. changes in phenology III. extinctions A) I only B) I and III only C) III only D) II and III only E) I, II, and III

B

7)After looking at the accompanying figure, what can be said about productivity in this ecosystem? A) Nothing can be said based on this information. B) About 90% of the energy is lost between most trophic levels. C) About 10% of the energy is lost between most trophic levels. D) Productivity increases with each trophic level.

B

11) 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.

C

13) Which letter represents an organism that could only be a primary consumer? A) A B) B C) C D) D E) E

C

15) What factor could potentially increase the length of a food chain? A) having a single species of herbivore feeding on cach plant species B) increased extinction rates of species in the food chain C) decrease in the amount of energy in a trophic level that is lost as it passes to the next higher level D) increase in the amount of energy in a trophic level that is lost as it passes to the next higher level

C

16) Detritivores A) recycle chemical elements directly back to primary consumers B) synthesize organic molecules that are used by primary producers C) convert organic materials from all trophic levels to inorganic compounds usable by primary producers D) secrete enzymes that convert the organic molecules of detritus into carbon dioxide and water E) may be autotrophic or heterotrophic

C

29) Which category in the figure makes available the highest productivity per square meter? A) tropical wet forest B) open ocean C) algal beds and reefs D) wetlands

C

31) Regarding soil and organic matter in humus, which of the following statements is TRUE? A) Humus is composed of inorganic nutrients, and organic matter is composed only of organic matter. B) Soil organic matter is completely decayed. C) Completely decayed soil organic matter is called humus. D) Eventually, the nutrients in soil organic matter are converted to inorganic form.

C

36) Which of the following human activities is impacting the water cycle the LEAST? A) increase in asphalt and concrete surfaces B) conversion of grasslands and forests into agricultural fields C) increased processing of salt water to freshwater D) increases in irrigated agriculture

C

41) In the nitrogen cycle, the bacteria that replenish the atmosphere with nitrogen are A) Rhizobium bacteria B) nitrogen fixing bacteria C) ones that use nitrogen-containing compounds as an electron acceptor. D) methanogenic protozoans E) nitrogen-fixing bacteria

C

43) A 3-hectare lake in the American Midwest suddenly has succumbed to an algal bloom. What is the likely cause of this in freshwater ecosystems? A) increased solar radiation B) introduction of nonnative tertiary consumer fish C) nutrient runoff D) accidental introduction of a prolific culture of algae E) iron dust blowing into the lake

C

48) Global warming refers to A) the increase in the total temperature across the oceans B) the increase in the total temperature across the continents C) the increase in the average temperature of the whole planet D) the increase in the average temperature across the continents E) the increase in the total temperature across the whole planet

C

49) Global climate change refers to A) the changes in precipitation patterns that result from global warming B) the changes in local temperature patterns that result from global warming C) the sum of the changes in local precipitation and temperature patterns that result from global warming D) the changes in ocean temperatures as a result of increased global carbon emissions E) the sum of the changes in local precipitation and temperature patterns that result from increases in ocean warming

C

53) Which of the following have contributed to the increase in the emission of CO2? I. increases in human population II. increases in per capita fossil-fuel use III. land use changes A)I B) I and II C) I, II, and III D) II

C

9) You own 300 acres of patchy temperate forest. Which one of the following actions would increase the net primary productivity of the area the most? A) removing the largest trees B) introducing 100 rabbits into the area C) planting 500 new trees D) relocating all of the deer found in the area

C

1) When primary producers expend energy to build new tissue, this is A) net primary productivity B) the amount of energy available to consumers C) maintenance costs D) net primary productivity and the amount of energy available to consumers E) maintenance costs and the amount of energy available to consumers

D

10) Approximately how many kilograms (kg) of carmivore (secondary consumer) biomass can be supported by a field plot containing 1000 kg of plant material? A) 10,000 B) 1000 C) 100 D) 10 E) 1

D

21) 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 for thermoregulation. D) It is eliminated as feces or is dissipated into space as heat, consistent with the second law of thermodynamics. E) It is recycled by decomposers to smaller and smaller forms until it finally breaks down to form soil.

D

25) Why is terrestrial productivity higher in equatorial climates? A) Productivity increases with temperature. B) Productivity inereases with water availability. C) Productivity increases with available sunlight. D) The answer is most likely a combination of the other responses.

D

34) Based on the experiment in the accompanying figure, which of the following are plausible reasons for the result? I. No nutrients evaporate now that vegetation is absent. II. Nutrients dissolve in the water running through the watershed. III. Nutrients are attached to small particles of sand or clay that leave the watershed. IV. Plant roots that held soil particles in place are no longer there. A) only I and III B) only II and IV C) only I, II, and IV D) only II, III, and IV E) only I, II, and II

D

37) Consider the global nitrogen cycle depicted in the accompanying figure. What is the limiting portion of the cycle for plants? A) industrial nitrogen fixation B) nitrogen lost to the atmosphere C) internal nitrogen cycling in the oceans D) nitrogen fixation by bacteria

D

56) Use the following graph and information to answer the question below. Flycatcher birds that migrate from Africa to Europe feed their nestlings a diet that is almost exclusively moth caterpillars. The graph shows the mean dates of arrival, bird hatching, and peak caterpillar season for the years 1980 and 2000. The shift in the peak of caterpillar season 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

D

6) What is the main reason for using food webs instead of food chains in analyzing ecosystems? I. Most organisms eat more than one type of food. II. Most organisms feed at several trophic levels. III. The decomposition cycle needs to be shown. A) only I B) only II C) only III D) only I and II E) I, II, and III

D

14) 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

E

20) 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 usually less than 20 percent efficient.

E

23) 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 lowest concentrations of fat-soluble toxins. D) Seal populations are larger than fish populations. E) Fish can potentially provide more food for humans than seal meat.

E

35) Consider the global water cycle depicted in the accompanying figure. Which one of the reserves contains the smallest percentage of global water? A) oceans B) rivers and lakes C) polar ice caps D) glaciers E) atmosphere

E

39) Which of the following is a source of human-fixed nitrogen? 1. industrially produced fertilizers II. cultivation of soybeans III. irrigation agriculture A) only I B) only II C) only III D) only II and III E) only I and II

E

40) Nitrogen is available to plants mostly in the form of A) nitrogen 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

E

45) Considering the global carbon cycle, where are humans having a great impact? I. terrestrial ecosystems II. oceans III. atmosphere A) only I B) only II C) only II D) only I and II E) I, II, and III

E

46) Why are changes in the global carbon cycle important? I. Burning reduces available carbon for primary producers and, therefore, primary consumers. II. Deforestation and suburbanization reduce an area's net primary productivity. III. Increasing atmospheric concentrations of carbon dioxide could alter Earth's climate. IV. By using fossil fuels we are destroying a nonrenewable resource. A) only I and III B) only Il and IV C) only I, II, and IV D) only II, III, and IV E) only I, II, II, and IV

E

47) Which of the following locations are large reservoirs for carbon for the carbon cycle? 1. atmosphere II. sediments and sedimentary rocks III. fossilized plant and animal remains (coal, oil, and natural gas) IV. plant and animal biomass A) only I and III B) only II and IV C) only I, II, and IV D) only II, III, and IV E) I, II, III, and IV

E