Elements of Ecology, 8e (Smith/Smith) Test Bank Chapter 25

Elements of Ecology, 8e (Smith/Smith) Chapter 25 Aquatic Ecosystems 25.1 Short Answer Questions 1) Classification of aquatic ecosystems is largely based on features of the ________ environment. Answer: physical Topic: Introduction to Chapter 25 2) The general term for flowing bodies of freshwater is ________. Answer: lotic Topic: Introduction to Chapter 25 3) Non-flowing water ecosystems, such as ponds and lakes, are also called ________ ecosystems. Answer: lentic Topic: Introduction to Chapter 25 4) In lakes and ponds, the open-water zone extending to the depth of light penetration is referred to as the ________ zone. Answer: limnetic Topic: Section 25.2 5) In lakes and ponds, the ________ zone is a shallow-water zone along the perimeter in which light reaches the bottom. Answer: littoral Topic: Section 25.2 6) In lakes and ponds, the depth at which respiration balances photosynthesis is referred to as the ________ depth of light. Answer: compensation Topic: Section 25.2 7) The tiny, photosynthetic, primary producers of open water such as desmids, diatoms, and filamentous algae are referred to as ________. Answer: phytoplankton Topic: Section 25.3 8) In the benthic zone of lakes and ponds, organisms that are attached to or move on a submerged substrate but do not penetrate it are referred to as ________. Answer: periphyton Topic: Section 25.3

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9) A relatively ________ lake is characterized by an abundance of nutrients, abundant algal growth, and shallow light penetration. Answer: eutrophic Topic: Section 25.4 10) Lakes that receive large amounts of organic matter from surrounding land, particularly in the form of humic materials that stain the water brown, are called ________ lakes. Answer: dystrophic Topic: Section 25.4 11) Flowing-water ecosystems often alternate two different but related habitats: the turbulent ________ and the quiet pool. Answer: riffle Topic: Section 25.5 12) ________ fish are those that live most of their lives in marine environments and return to freshwater to spawn. Answer: Anadromous Topic: Section 25.5 13) Invertebrates that feed on the algal coating of stones and rubble in streams and rivers are referred to as ________. Answer: grazers Topic: Section 25.6 14) Streams generally have a(n) ________ temperature at their headwaters than toward their outlet. Answer: lower Topic: Section 25.7 15) When rivers flow into the ocean, they create a zone that mixes freshwater with saltwater referred to as a(n) ________. Answer: estuary Topic: Section 25.8 16) The water above the continental shelf belongs to the ________ province of the pelagic zone. Answer: neritic Topic: Section 25.9 17) The zone in the ocean from the surface to approximately 200 meters deep is called the ________ zone. Answer: epipelagic Topic: Section 25.9

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18) Smaller than diatoms, the ________, which include tiny cyanobaceteria, haptophtyes, and coccolithophores, make up the largest biomass in temperate and tropical water. Answer: nanoplankton Topic: Section 25.10 19) Reef-building corals have a symbiotic relationship with algal cells called ________ that live within the cells of corals. Answer: zooxanthella Topic: Section 25.12 20) A(n) ________ is a ring of coral reefs and islands surrounding a lagoon that is formed when a volcanic mountain subsides beneath the surface. Answer: atoll Topic: Section 25.12 25.2 Multiple-Choice Questions 1) Which of the following bodies of water best represents a lotic ecosystem? A) salt pond B) marsh C) oxbow lake D) stream Answer: D Topic: Introduction to Chapter 25 2) ________ are mountainous lakes that have been carved by glacial erosion and deposition. A) Marshes B) Oxbows C) Reservoirs D) Tarns Answer: D Topic: Section 25.1 3) In lakes and ponds, photosynthesis occurs primarily in the A) benthic zone. B) profundal zone. C) limnetic zone. D) lotic zone. Answer: C Topic: Section 25.2

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4) In ponds and lakes, the zone beneath the depth of effective light penetration but above the bottom is referred to as the A) littoral zone. B) limnetic zone. C) profundal zone. D) benthic zone. Answer: C Topic: Section 25.2 5) In lakes and ponds, decomposition occurs primarily in the A) benthic zone. B) littoral zone. C) limnetic zone. D) profundal zone. Answer: A Topic: Section 25.2 6) In lakes and ponds, phytoplankton and zooplankton are most abundant in the A) benthic zone. B) littoral zone. C) limnetic zone. D) profundal zone. Answer: C Topic: Section 25.3 7) In lakes and ponds, oxygen concentrations are lowest in the A) benthic zone. B) littoral zone. C) limnetic zone. D) profundal zone. Answer: A Topic: Section 25.3 8) Which of the following lakes is likely to be the most oligotrophic? A) small and shallow B) small and deep C) large and shallow D) large and deep Answer: D Topic: Section 25.4

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9) In streams and rivers, decomposition occurs primarily in A) riffles. B) pools. C) runs. D) rapids Answer: B Topic: Section 25.5 10) Streams are classified according to orders. If two first order streams join, flow through a valley, and are joined by another first order stream, what is the final stream order? A) first order B) second order C) third order D) fourth order Answer: B Topic: Section 25.5 11) Invertebrates that feed on coarse particulate organic matter (CPOM), such as leaves that fall into streams and rivers, are referred to as A) shredders. B) gougers. C) grazers. D) collectors. Answer: A Topic: Section 25.6 12) As a stream or river descends, it generally grows A) faster and cooler. B) slower and warmer. C) faster and warmer. D) slower and cooler. Answer: B Topic: Section 25.7 13) Shredders, collectors, and small predatory fish such as sculpins, darters, and trout are the dominant organisms collectively found in A) estuaries. B) small headwater streams. C) medium-sized streams. D) large rivers. Answer: B Topic: Section 25.7

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14) Semi-enclosed areas of the coastal ocean where seawater is diluted and partially mixed with freshwater coming from the land are referred to as A) eddies. B) coastal reservoirs. C) tidal basins. D) estuaries. Answer: D Topic: Section 25.8 15) Many physical features dictate life in an estuary. The physical feature with the most influence on organismal distribution is A) light. B) nutrients. C) salinity. D) temperature. Answer: C Topic: Section 25.8 16) The oxygen-minimum layer of an ocean occurs in the A) abyssalpelagic zone. B) bathypelagic zone. C) epipelagic zone. D) mesopelagic zone. Answer: D Topic: Section 25.9 17) The dominant autotrophs of the open water are A) phytoplankton. B) kelp. C) seagrasses. D) stromatolites. Answer: A Topic: Section 25.10 18) In the ocean, swimming organisms that can move at will in the water column are referred to as A) periphyton. B) zooplankton. C) megaplankton. D) nekton. Answer: D Topic: Section 25.10

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19) The organisms living on the bottom of the ocean are collectively referred to as A) nekton. B) benthos. C) meiofauna. D) epifauna. Answer: B Topic: Section 25.11 20) The benthic community of an ocean, with the exception of hydrothermal vents, is best described as A) completely heterotrophic and very diverse. B) completely autotrophic and very diverse. C) completely phototrophic and not very diverse. D) mostly heterotrophic and not very diverse. Answer: A Topic: Section 25.11 21) In hydrothermal vent communities, autotrophic organisms obtain energy by oxidizing A) reduced sulfur compounds. B) carbon dioxide. C) sodium chloride. D) metals such as copper and iron. Answer: A Topic: Section 25.11 22) The cells of reef-building corals are inhabited by symbiotic species of A) algae. B) fungi. C) bacteria. D) cyanobacteria. Answer: A Topic: Section 25.12 23) Coral reefs grow best where water is A) warm, shallow, and clear. B) warm, deep, and clear. C) cold, shallow, and clear. D) cold, deep, and murky. Answer: A Topic: Section 25.12

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24) The productivity of oceans is greatest in the A) neritic province at tropical latitudes. B) oceanic province at tropical latitudes. C) neritic province at temperate latitudes. D) oceanic province at temperate latitudes. Answer: C Topic: Sections 25.13 25) If a stream has an average depth of 3 meters, an average width of 4 meters, and an average stream velocity of 0.25 m/s, what is the discharge rate or streamflow (Q)? A) 0.187 m3/s B) 3 m3/s C) 12 m3/s D) 48 m3/s Answer: B Topic: Quantifying Ecology 25.1: Streamflow 25.3 True/False Questions 1) Non-flowing water bodies, such as lakes, are referred to as lotic ecosystems. Answer: FALSE Topic: Introduction to Chapter 25 2) Lakes can be formed from both geological and nongeological activity. Answer: TRUE Topic: Section 25.1 3) In the profundal zone of a lake or pond, the rate of photosynthesis exceeds the rate of respiration. Answer: FALSE Topic: Section 25.2 4) Phytoplankton thrive in the limnetic zone of lakes and ponds. Answer: TRUE Topic: Section 25.3 5) Oxygen concentrations are relatively high in the bottom ooze of lakes and ponds. Answer: FALSE Topic: Section 25.3 6) Eutrophic lakes are typically clear, with little algal growth. Answer: FALSE Topic: Section 25.4 7) In rivers and streams, the invertebrates that scrape algae off rocks are referred to as shredders. Answer: FALSE Topic: Section 25.6 8 Copyright © 2012 Pearson Education, Inc.

8) As a stream flows down its course, it generally becomes warmer and slower. Answer: TRUE Topic: Section 25.7 9) Most estuarine organisms are benthic. Answer: TRUE Topic: Section 25.8 10) Inflowing river waters most often impoverish rather than fertilize estuaries. Answer: TRUE Topic: Section 25.8 11) Photosynthesis in the ocean takes place mostly in the mesopelagic zone. Answer: FALSE Topic: Section 25.9 12) The deepest water of an ocean in deep-sea trenches and canyons is referred to as the hadalpelagic zone. Answer: TRUE Topic: Section 25.9 13) Unlike phytoplankton, which are at the mercy of currents, zooplankton can move at will within a current. Answer: FALSE Topic: Section 25.10 14) Many zooplankton migrate to the surface to graze on phytoplankton during the day and retreat to deeper water during the night. Answer: FALSE Topic: Section 25.10 15) Swimming organisms in the ocean that are able to move at will in the water column are referred to as nekton. Answer: TRUE Topic: Section 25.10 16) Bioluminescence reaches its greatest development in the mesopelagic zone of an ocean. Answer: TRUE Topic: Section 25.10 17) The organisms responsible for the majority of primary production in marine environments are the copepods. Answer: FALSE Topic: Section 25.10

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18) Because of the high pressure and cold temperatures, few species of organisms survive in the deep benthic zone of the ocean. Answer: FALSE Topic: Section 25.11 19) Organisms living in deep-sea hydrothermal vents do not need light to obtain their energy. Answer: TRUE Topic: Section 25.11 20) Coral reefs occur in nutrient-poor areas of the ocean. Answer: TRUE Topic: Section 25.12 21) Barrier reefs are separated from land by shallow lagoons. Answer: TRUE Topic: Section 25.12 22) Because the thermocline is permanent in tropical oceans, little vertical mixing occurs, resulting in low productivity. Answer: TRUE Topic: Section 25.13 23) The Colorado River in western North America is so overused that it disappears before it reaches the mouth of the Gulf of California. Answer: TRUE Topic: Ecological Issues: Dams: Regulating the Flow of River Ecosystems 24) The velocity of water in a stream channel is greater along the margins of the channel than in the center of the channel. Answer: FALSE Topic: Quantifying Ecology 25.1: Streamflow 25.4 Essay Questions 1) Describe three processes that can lead to the formation of a lake or pond. Topic: Section 25.1 2) Describe the types of organisms and biological activities that occur within the littoral, limnetic, and benthic zones of a lake. Topic: Section 25.3 3) Describe the differences between eutrophic and oligotrophic lakes. What conditions lead to the formation of each? Topic: Section 25.4

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4) Based on their feeding behavior, describe three major groups of invertebrates that inhabit flowing water. Topic: Section 25.7 5) Describe the physical conditions to which organisms living in an estuary must be adapted. Topic: Section 25.8 6) Describe the differences between phytoplankton, zooplankton, and nekton. How do they interact with one another? Topic: Section 25.10 7) Describe the microbial loop and how it relates to the plankton food chain. Topic: Section 25.10 8) Describe three types of reefs and how they are formed. Topic: Section 25.12 9) Describe how primary productivity of the oceans is regulated by light and nutrients. Topic: Section 25.13

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