Chapter 6—Marine Microbes. Answers Explained

MULTIPLE CHOICE 1. The most abundant microbes in the marine environment are: a. bacteria. b. diatoms. c. foraminiferans. d. viruses. e. dinoflagellates. D PTS: 1 DIF: Recall REF: 123 2. Viruses are not ...

MULTIPLE CHOICE 1. The most abundant microbes in the marine environment are: a. bacteria. b. diatoms. c. foraminiferans. d. viruses. e. dinoflagellates. D PTS: 1 DIF: Recall REF: 123 2. Viruses are not considered "living" by some biologists because they a. have no metabolism. b. do not reproduce. c. cannot move. d. contain protein. A PTS: 1 DIF: Recall REF: 123 3. Virus replication only occurs a. when conditions stress the virus. b. at regular intervals. c. inside a host cell. d. outside of eukaryote cells. e. when virus particles undergo binary fission. C PTS: 1 DIF: Recall REF: 123 4. A phage a. can be found in all living organisms. b. is specific to a particular organism. c. is found in mammals. d. is specific for bacteria. e. is specific for vertebrates. D PTS: 1 DIF: Recall REF: 124 5. Virus size is a. 300 to 400 m. b. 10 to 400 mm. c. 10 to 200 cm. d. 10 to 400 nm. e. 300 to 400 mm. D PTS: 1 DIF: Recall REF: 124 6. Outside a host cell a virus is called a(n): a. capsid. b. virion. c. nucleocapsid. d. envelope. e. glochidia. B PTS: 1 DIF: Recall REF: 124 7. The protein coat covering the nucleic acid core of the virus is called the a. capsid. b. virion. c. nucleocapsid. d. envelope. e. membrane. A PTS: 1 DIF: Recall REF: 124 8. The combination of a virus's genetic material and protein is called the a. capsid. b. virion. c. nucleocapsid. d. envelope. e. transfer RNA. C PTS: 1 DIF: Recall REF: 124 9. You are a virologist studying a particularly pathogenic virus that infects sea turtles. In the course of your research, you discover that the virus is destroyed by a protein-digesting enzyme. The structure most vulnerable to this enzyme must be the viral a. membrane. b. envelope. c. DNA. d. capsid. D PTS: 1 DIF: Application REF: 124 10. A virus's nucleocapsid is sometimes covered with a(n): a. capsid. b. virion. c. organic material. d. envelope. e. membrane. D PTS: 1 DIF: Recall REF: 124 11. A virus with a capsid with twenty triangular faces is called: a. icosahedral. b. helical. c. binal. d. filamentous. e. dodecahedral. A PTS: 1 DIF: Recall REF: 124 12. A viral lytic cycle is characterized by: a. rapid infection and emergence. b. rapid infection, replication of nucleic acids and proteins, assembly of virions and release by rupture. c. a virus remaining in the host cell then being released. d. a viral nucleic acid being inserted into the host genome and possibly residing through multiple cell divisions prior to lytic. B PTS: 1 DIF: Synthesis REF: 125–126 13. A viral lysogenic cycle is characterized by: a. rapid infection and emergence. b. rapid infection, replication of nucleic acids and proteins, assembly of virions and release by rupture. c. a virus remaining in the host cell then being released. d. a viral nucleic acid being inserted into the host genome and possibly residing through multiple cell divisions prior to lytic. D PTS: 1 DIF: Synthesis REF: 125–126 14. The abundance and diversity of marine viruses are considered a. low abundance with high diversity. b. high abundance and low diversity. c. low abundance and low diversity. d. high abundance and high diversity. D PTS: 1 DIF: Recall REF: 125 15. Some viruses can change geochemical cycles leading to: a. a change in seawater pH. b. reduction in surface oxygen. c. modification of salinity. d. an effect on global warming. e. increased geothermal activity. D PTS: 1 DIF: Recall REF: 126 16. Viruses can control host population a. by reducing their numbers. b. by modifying their growth rate. c. by increasing their capacity to expand. d. by making them more attractable to predators. e. by attaching to the host membrane, causing the host cell to sink. A PTS: 1 DIF: Recall REF: 126 17. Bacteria belong to the domain a. Eubacteria. b. Eukarya. c. Archaea. d. Animalia. e. Protista. A PTS: 1 DIF: Recall REF: 127 18. Bacteria reproduce by: a. meiosis. b. cell fusion. c. binary fission. d. cloning. e. auxospore formation. C PTS: 1 DIF: Recall REF: 127 19. The process of producing high-energy foods from inorganic compounds using sunlight energy is called: a. heterotrophy. b. chemosynthesis. c. photosynthesis. d. grazing. e. solar irradiation. C PTS: 1 DIF: Recall REF: 130 | 132 20. The process of producing food from inorganic compounds using high energy compounds as a source of energy is called: a. photosynthesis. b. chemosynthesis. c. heterotrophy. d. grazing. e. solar irradiation. B PTS: 1 DIF: Recall REF: 131 21. Chemosynthetic bacteria are unique: a. in not requiring CO2. b. because they use energy derived from chemicals. c. because they can produce food with low light. d. and are very common in the twilight depths. e. because many forms are also bioluminescent. B PTS: 1 DIF: Recall REF: 131 22. Facultative anaerobic bacteria a. do not tolerate oxygen. b. respire in low oxygen. c. are chemosynthetic. d. require oxygen to perform photosynthesis. e. are common in open water samples. B PTS: 1 DIF: Recall REF: 131 23. Anaerobic organisms live in ____ areas. a. nitrogen-free. b. oxygen-rich. c. oxygen-free. d. hydrogen-free. e. carbon-free. C PTS: 1 DIF: Recall REF: 131 24. The process where DNA is duplicated and then the cell divides into two cells is called: a. mitosis. b. meiosis. c. binary fusion. d. auxospore. e. fusion. C PTS: 1 DIF: Recall REF: 127 25. A rod-shaped bacteria is called: a. coccus. b. auxospore. c. bacillus. d. bacteriophage. e. spirillus. C PTS: 1 DIF: Recall REF: 127 26. A spherical shaped bacteria is called: a. coccus. b. auxospore. c. bacillus. d. bacteria phage. e. spirillus. A PTS: 1 DIF: Recall REF: 127 27. Which primary producer listed below is considered the most abundant life form in the sea? a. Dunaliella b. Synechoccus c. Methanococcus d. Pryolobus e. Prochlorococcus E PTS: 1 DIF: Recall REF: 128 28. The pigment ____ is commonly found in bacteria but not land plants. a. chlorophyll a b. chlorophyll b c. xanthophyll d. phycocyanin e. carotene. D PTS: 1 DIF: Recall REF: 130 29. Accessory photosynthetic pigments are important because: a. they can capture different light wavelengths. b. they enable chromatic adaptation with depth and seasons. c. they shield the cell against damaging wavelengths. d. all the above. D PTS: 1 DIF: Synthesis REF: 130 30. A structure formed from the combination of cyanobacterial microbes and sediments is called: a. a coral reef. b. a bacteria reef. c. a stromatolite. d. a stalactite. e. a stalagmite. C PTS: 1 DIF: Recall REF: 130 31. The absorption of external organic matter by bacteria is called: a. heterotrophy. b. autotrophy. c. tertiary. d. osmotrophy. e. omnivory. D PTS: 1 DIF: Recall REF: 128 32. Heterotrophic bacteria are able to break down large food items a. by ingesting them with pseudopods. b. with exoenzymes. c. by breaking them up with cilia. d. by crushing with their larger relative size. e. by using their cell membranes to pinch the food into smaller pieces. B PTS: 1 DIF: Recall REF: 131 33. An important role of bacteria is: a. primary producers. b. decomposers. c. nitrogen fixation. d. all of the above D PTS: 1 DIF: Synthesis REF: 131 34. Nutrient recycling in the marine environment is performed by: a. cyanobacteria. b. heterotrophic bacteria. c. autotrophic bacteria. d. purple bacteria. e. sulfur bacteria. B PTS: 1 DIF: Recall REF: 131 35. Nitrogen fixation is carried out by: a. nitrifying bacteria. b. prochlorophytes. c. cyanobacteria. d. all heterotrophic bacteria. e. only spirilli-shaped bacteria. C PTS: 1 DIF: Recall REF: 132–133 36. A special structure on certain cyanobacteria for nitrogen fixation is called a(n): a. ammonia cyst. b. homocyst. c. heterocyst. d. nematocyst. e. pneumatocyst. C PTS: 1 DIF: Recall REF: 129 | 133 37. Nitrogen fixation and nitrification are directly important processes for: a. heterotrophic animals. b. heterotrophic bacteria. c. autotrophic organisms. d. fungi. e. viruses. C PTS: 1 DIF: Recall REF: 133 38. A bacteria sample is taken from the immediate vicinity of a hydrothermal vent. You would expect for it to most likely contain a. diatoms. b. hyperthermophiles. c. lignicolous fungi. d. cyanobacteria. B PTS: 1 DIF: Application REF: 136 39. Zooxanthellae are members of the following group of Eukaryotes: a. diatoms. b. coccolithophores. c. amoebas. d. dinoflagellates. e. ciliates. D PTS: 1 DIF: Recall REF: 145 40. Harmful algal bloom toxins are produced by: a. diatoms. b. coccolithophores. c. amoebas. d. dinoflagellates. e. radiolarians. D PTS: 1 DIF: Recall REF: 146 41. Diatoms, coccolithophores and silicoflagellates all belong to the domain: a. Eukarya. b. Eubacteria. c. Archaea. d. Anthophyta. e. Protista. A PTS: 1 DIF: Recall REF: 139–143 42. All of following marine microbes have hard skeletal parts that sink to the bottom, forming oceanic sediments, except a. radiolarians. b. coccolithophores. c. foraminiferans. d. diatoms. e. fungi. E PTS: 1 DIF: Synthesis REF: 136–137 | 141 | 143 | 149 | 150 43. The frustule of diatoms is made of: a. cellulose. b. calcium carbonate. c. silica. d. protein. e. starch. C PTS: 1 DIF: Recall REF: 140 44. The deposits of the following phytoplankton are used commercially in polishes and filtering devices: a. dinoflagellates. b. foraminiferans. c. coccolithophores. d. diatoms. e. radiolarians. D PTS: 1 DIF: Recall REF: 141 45. Pseudopods are structures that are primarily found in: a. silicoflagellates. b. amoeboid protozoans. c. coccolithophores. d. diatoms. e. dinoflagellates. B PTS: 1 DIF: Recall REF: 147 46. You add a weak acid solution to a sample of foraminifera shells, and they bubble and fizz. This tells you that the external shells of foraminiferans are composed of: a. silica. b. protein. c. cellulose. d. calcium carbonate. e. starch. D PTS: 1 DIF: Application REF: 149 47. The following amoeboid protozoans are important sources of silica deposits in some areas of the world: a. diatoms. b. silicoflagellates. c. radiolarians. d. foraminiferans. e. ciliates. C PTS: 1 DIF: Recall REF: 150 48. Tintinnids are examples of the following protozo a. radiolarians. b. ciliates. c. diatoms. d. foraminiferans. e. dinoflagellates. B PTS: 1 DIF: Recall REF: 146 | 148 49. The ecological role of fungi is that of: a. decomposers. b. producers. c. grazers. d. predators. e. herbivores. A PTS: 1 DIF: Recall REF: 137 50. A very close association with two species is called: a. adjoining. b. symbiosis. c. predator -prey. d. host-fungus. e. competition. B PTS: 1 DIF: Recall REF: 133 TRUE/FALSE 51. The only autotrophic bacteria are chemosynthetic bacteria. F PTS: 1 REF: 128 52. Deep-sea vent bacteria do not rely on the sun as a source of energy. T PTS: 1 REF: 131 53. Since purple and green bacteria do not use water in their autotrophic processes, they are not photosynthetic. F PTS: 1 REF: 131 54. Nitrifying bacteria are important in the conversion of nitrogen gas to usable forms of nitrogen. F PTS: 1 REF: 132–133 55. Chemosynthesis is less efficient than photosynthesis. T PTS: 1 REF: 131 56. Amoeboid protozoans are autotrophic. F PTS: 1 REF: 147 57. The toxins of dinoflagellates are destroyed by cooking or heating. F PTS: 1 REF: 146 58. Diatoms reproduce by binary fission. T PTS: 1 REF: 140–141 59. Ciliates are autotrophic members of the phytoplankton community. F PTS: 1 REF: 146 60. Fungi are surrounded by a cell wall made of chitin. T PTS: 1 REF: 136 61. Fungi are usually found in pelagic habitats. F PTS: 1 REF: 136 MATCHING Match the description with the most closely associated term. a. icosahedral heads with helical tails b. protein subunit of the capsid spiral around the central core of the nucleic acid c. capsid with twenty triangular faces 62. Icosahedral 63. Helical 64. Binal 62. C PTS: 1 REF: 124–125 63. B PTS: 1 REF: 124–125 64. A PTS: 1 REF: 124–125 Match the bacteria-caused process with the most closely associated characteristic. a. alteration of the electrical charge b. settling out of large particles c. alteration of the pH 65. Consolidation 66. Lithification 67. Sedimentation 65. A PTS: 1 REF: 131 66. C PTS: 1 REF: 131 67. B PTS: 1 REF: 131 Match the words with the most closely associated words. a. NH4+ to NO2- and NO3- b. can break the bonds in N2 molecules c. N2 to NH3 68. Nitrogenase 69. Nitrogen fixation 70. Nitrification 68. B PTS: 1 REF: 132–133 69. C PTS: 1 REF: 132–133 70. A PTS: 1 REF: 132–133 Match the words with the most closely associated phrase. a. conidiospores b. budding c. ascocarp 71. Marine yeast asexual reproduction 72. Filamentous marine fungi asexual reproduction 73. Filamentous sexual reproduction 71. B PTS: 1 REF: 138 72. A PTS: 1 REF: 138 73. C PTS: 1 REF: 138 Match the description with the most closely associated word. a. DHA fatty acid b. planktonic decomposer c. wasting disease 74. Labyrinthulids 75. Thraustochytrids 76. Schizochytrium 74. C PTS: 1 REF: 142 75. B PTS: 1 REF: 142 76. A PTS: 1 REF: 142 Match the characteristic with its most closely associated organisms. a. disc-shaped calcareous scales b. membranous sacs c. silicon frustules 77. Diatoms 78. Coccoliths 79. Alveolates 77. C PTS: 1 REF: 139–143 78. A PTS: 1 REF: 139–143 79. B PTS: 1 REF: 139–143 Match the dinoflagellate characteristic with those it is most closely associated with. a. either osmotrophy or phagotrophy b. important symbionts of coral c. paralytic shellfish poisoning 80. Zooxanthellae 81. "Red Tide" 82. Mixotrophic 80. B PTS: 1 REF: 145–146 81. C PTS: 1 REF: 145–146 82. A PTS: 1 REF: 145–146 Match the description with the most closely associated word. a. have a lorica b. few body cilia c. dense and uniform distribution of cilia 83. Scuticocilates 84. Oligotrichs 85. Tinitinnids 83. C PTS: 1 REF: 146 84. B PTS: 1 REF: 146 85. A PTS: 1 REF: 146 Match the words with the most closely associated group. a. collar of microvilli traps bacteria prey b. siliceous perforated shell c. reticulopods 86. Foraminiferans 87. Radiolarians 88. Choanoflagellates 86. C PTS: 1 REF: 146–150 87. B PTS: 1 REF: 146–150 88. A PTS: 1 REF: 146–150 Match the description with the most closely associated group. a. prokaryote in some ways similar to eukaryotes b. original inhabitants of the sea c. nucleus and membrane-bound organelle 89. Eubacteria 90. Archaea 91. Eukarya 89. B PTS: 1 REF: 127 90. A PTS: 1 REF: 135 91. C PTS: 1 REF: 136 ESSAY 92. Briefly explain why viruses are not considered living organisms. 93. Briefly describe 3 ecological roles of viruses. PTS: 1 DIF: Synthesis REF: 126 94. What would happen if organisms that play the role of heterotrophic bacteria did not exist in the marine environment? 95. Given that oxygen is toxic to anaerobic bacteria, describe how they must have adapted to survive in the present environmental conditions on Earth. 96. Compare and contrast aerobic and aerobic bacterial photosynthesis in terms of a) the source of electrons used by each; b) the final products of both reactions. 97. What is meant by the term "paralytic shellfish poisoning"? What are the symptoms, and what organisms are responsible for this disease? 98. What is diatomaceous earth? How is it used commercially? 99. Describe the feeding behavior and biology of amoeboid protozoans. 100. You are asked to determine whether sulfur bacteria are active in a particular area of an estuary. What observations or tests can you perform to confirm this activity? 101. What is the importance of nitrogen-fixation to autotrophic organisms? 102. Describe the symbiotic relationship between zooxanthellae and their hosts. How do both benefit from the relationship? 103. Toxic dinoflagellates can directly harm other organisms during bloom periods by secreting their toxins in the water or by being consumed and concentrated in the tissues of filter-feeding organisms. Can you think of ways in which blooms of non-toxic dinoflagellates may harm other organisms in the water? 104. Based on your knowledge of the distribution of CO2 in the marine environment and the pattern of pressure with depth, explain why calcium carbonate deposits of coccolithophores and foraminiferans are not found below 5000 m.