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Methane hydrates found at the bottom of the ocean


A) vastly exceed in amount the world's current known natural gas reserves.
B) float to the surface where they are consumed by methylotrophs.
C) are only formed in areas of thermal heating.
D) all of the choices

E) All of the above
F) A) and C)

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Marine microbes inhabit sediments on the ocean floor at a depth of up to at least


A) one foot.
B) ten feet
C) 100 feet
D) 0.6 kilometers

E) A) and B)
F) All of the above

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Which of the following statements concerning the microbial loop is not true?


A) microbes consume dissolved organic matter
B) marine viruses contribute to the production of dissolved organic matter
C) microbes constitute particulate organic matter for zooplankton consumption
D) all of the statements are true

E) A) and D)
F) C) and D)

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Salt marshes differ from estuaries in that the freshwater input in salt marshes is from a single source.

A) True
B) False

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The largest fraction of saltwater is that which is frozen at the Earth's polar regions.

A) True
B) False

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Thiomargarita species store large amounts of ____________ in huge internal vacuoles.


A) nitrate
B) sulfate
C) oxygen
D) hydrogen sulfide

E) A) and D)
F) B) and D)

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Competitive advantages for cyanobacteria in the aquatic environment include


A) the ability of many to fix nitrogen.
B) the production of toxins to resist predation.
C) the production of hydroxamates to bind iron.
D) all of the choices

E) B) and D)
F) None of the above

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Barophilic bacteria


A) tolerate high concentration of barium.
B) grow at pressures up to 1,100 atm.
C) grow only in environments of reduced atmospheric pressure, such as found at high elevation.
D) require high concentrations of H2S gas for growth.

E) A) and B)
F) C) and D)

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The buffering effect of the balance between carbon dioxide, bicarbonate, and carbonate is stronger in freshwater than it is in the marine environment.

A) True
B) False

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Water ecosystems become eutrophic when there is


A) nutrient enrichment of waters.
B) nutrient removal from waters.
C) acidification of waters.
D) deoxygenation of waters.

E) C) and D)
F) All of the above

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When direct examination of virioplankton is carried out by transmission electron microscopy, the numbers obtained are reported as


A) plaque-forming units
B) virus-like particles
C) viral potential
D) particulate organic matter

E) A) and B)
F) A) and C)

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In which of the following types of waters do seasonal climatic temperature changes result in distinct chemical and microbial stratification?


A) oceans
B) lakes in temperate areas
C) lakes in tropical areas
D) fast flowing rivers

E) B) and C)
F) All of the above

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The open ocean is a(n) _____________ environment.


A) eutrophic
B) oligotrophic
C) neotrophic
D) phylotrophic

E) A) and D)
F) B) and C)

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The importance of phage-mediated lateral gene transfer by virioplankton was illustrated by the fact that cyanophages thought to infect Synechococcus and Prochlorococcus carry the structural gene for


A) nitrogenase.
B) phycocyanin production.
C) a photosynthetic reaction center protein.
D) all of the choices

E) None of the above
F) C) and D)

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The biologically available carbon that is produced within large, lentic rivers and lakes is called ___________.

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The solubility of oxygen in water will change in which way when the water temperature is lowered?


A) No change will occur.
B) The solubility will increase.
C) The solubility will decrease.
D) The solubility will first decrease then increase.

E) A) and B)
F) C) and D)

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Winogradsky columns


A) are typically used to isolate aquatic protozoa.
B) are used as a model system for studying microbial interactions.
C) are used in the process of isolating nanobacteria.
D) are used in the process of isolating aquatic viruses (virioplankton) .

E) C) and D)
F) None of the above

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Among the eukaryotic microbes in the phytoplankton, the ________ are most noted for their contribution to carbon fixation.


A) dinoflagellates
B) green algae
C) diatoms
D) cyanobacteria

E) B) and C)
F) All of the above

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The chemolithotrophs that metabolize reduced sulfur compounds using oxygen as a terminal electron acceptor in the Winogradsky column include


A) Desulfovibrio.
B) Beggiatoa.
C) Chromatium.
D) cyanobacteria.

E) A) and D)
F) All of the above

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The discharge of high levels of microbial nutrients into marine environments has


A) resulted in the production of large hypoxic or anoxic regions.
B) had negative impacts on shellfish and other bottom-dwelling marine animals.
C) resulted in algal blooms and red tides that have killed marine mammals.
D) all of the choices

E) B) and C)
F) A) and B)

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