Question 1

Which of the following processes does denitrification contribute to?

Accepted Answer

A)   acid rain
B)   ozone depletion
C)   global warming
D)   acid rain, ozone depletion, and global warmingE) None of the above
F) A) and D)

Question 2

Lysis of marine algae and cyanobacteria releases the major osmoregulatory solute,dimethylsulfoniopropionate (DMSP) ,which is degraded into the most abundant organic S compound in nature,________.

Accepted Answer

A)   dimethyl sulfide (CH₃-S-CH₃) 
B)   hydrogen sulfide (H₂S) 
C)   gypsum (CaSO₄) 
D)   elemental sulfur (Sᵒ) E) B) and D)
F) A) and B)

Question 3

What would the result be when a soil is supplemented with S⁰?

Accepted Answer

A)   dimethyl sulfide production due to mixotrophs
B)   organic carbon production due to anaerobes
C)   soil acidification due to chemolithotrophs
D)   syntrophic utilization of sulfiteE) All of the above
F) C) and D)

Question 4

Why does the burning of fossil fuels cause an imbalance within the carbon cycle? What is the consequence of this imbalance? Include a diagram of the carbon cycle to illustrate your answer.

Accepted Answer

Answers should include a diagram similar...

Question 5

Sulfide is toxic to respiring organisms,because it can combine with metals present in ________ that serve a critical function in respiration.

Accepted Answer

A)   glycolysis enzymes
B)   oxidases
C)   NADH
D)   cytochromesE) All of the above
F) None of the above

Question 6

The Ca cycle is tightly coupled to the

Accepted Answer

A)   carbon cycle through calcium carbonate formation in ocean waters.
B)   phosphorus cycle through calcium phosphate formation in sediments and rocks.
C)   silica cycle through calcium silicate formation in coastal ocean sediments.
D)   nitrogen cycle because nitrogenase requires calcium ions.E) A) and D)
F) All of the above

Question 7

What reaction is catalyzed by mercuric reductase?

Accepted Answer

A)   CH₃HgCH₃ to Hg²⁺
B)   CH₃Hg⁺ to Hg²⁺
C)   Hg⁴⁺ to Hg²⁺
D)   Hg²⁺ to Hg⁰E) C) and D)
F) None of the above

Question 8

Climate scientists are developing methane hydrates to decrease the effects of global warming.

Accepted Answer

A) True 
 B)False

Question 9

The ocean has mitigated the impact of anthropogenic carbon dioxide production by

Accepted Answer

A)   absorbing 500 billion tons of atmospheric carbon dioxide.
B)   absorbing over 80% of the trapped heat energy.
C)   storing 600 billion tons of organic carbon.
D)   absorbing 500 billion tons of atmospheric carbon dioxide and over 80% of the trapped heat energy.E) C) and D)
F) A) and D)

Question 10

What are the similarities and differences between the Fe cycle and Ca cycle?

Accepted Answer

Both Fe and Ca cycle between insoluble a...

Question 11

Studying the redox cycling of Fe in the environment has led to the discovery

Accepted Answer

A)   of bacteria that transfer electrons long distances and generate electric currents.
B)   of bacteria that destroy toxic metal ions.
C)   of archaea that have Fe in their cell walls.
D)   that Fe limits primary production in terrestrial ecosystems.E) A) and B)
F) A) and C)

Question 12

Bacterial oxidation of Fe²⁺ occurs BEST under which environmental condition?

Accepted Answer

A)   cold temperature
B)   high sunlight
C)   low (acidic)  pH
D)   nutrient-repleteE) A) and B)
F) A) and C)

Question 13

Microbial activity generates methylmercury,which is much less toxic than the mercuric ion.

Accepted Answer

A) True 
 B)False

Question 14

Ocean acidification decreases the precipitation of calcium carbonate and thus will probably affect the cycling of Ca and other nutrients in the ocean.

Accepted Answer

A) True 
 B)False

Question 15

The metabolic process of ammonification ________ ammonia.

Accepted Answer

A)   oxidizes
B)   produces
C)   reduces
D)   transformsE) C) and D)
F) None of the above

Question 16

What is a characteristic of a deep sea marine cold seep/vent?

Accepted Answer

A)   acidic
B)   luminous
C)   low pressure
D)   rich in methaneE) All of the above
F) B) and C)

Question 17

Mercury can serve as a transcriptional activator in the regulation of certain genes.

Accepted Answer

A) True 
 B)False

Question 18

The disposal of garbage or sewage in the ocean is known to cause the sudden growth of sulfate reducers.

Accepted Answer

A) True 
 B)False

Question 19

More carbon is present in dead organic material on Earth than in living organisms.

Accepted Answer

A) True 
 B)False

Question 20

One important difference between the C,N,and S cycles and the P,Ca,and Si cycles is that

Accepted Answer

A)   P, Ca, and Si are NOT cycled in terrestrial environments.
B)   the P, Ca, and Si cycles do NOT involve redox changes or gaseous forms that can alter Earth's atmospheric chemistry.
C)   the P, Ca, and Si cycles do NOT involve microbial activity.
D)   the P, Ca, and Si cycles are NOT affected by global warming or other human activity.E) B) and C)
F) All of the above

Exam 20: Nutrient Cycles

What are the similarities and differences between the Fe cycle and Ca cycle?

Correct AnswerverifiedBoth Fe and Ca cycle between insoluble a...View AnswerShow Answer

The disposal of garbage or sewage in the ocean is known to cause the sudden growth of sulfate reducers.

Correct AnswerverifiedShow Answer

Which of the following processes does denitrification contribute to?

Correct AnswerverifiedShow Answer

More carbon is present in dead organic material on Earth than in living organisms.

Correct AnswerverifiedShow Answer

What reaction is catalyzed by mercuric reductase?

Correct AnswerverifiedShow Answer

Studying the redox cycling of Fe in the environment has led to the discovery

Correct AnswerverifiedShow Answer

The ocean has mitigated the impact of anthropogenic carbon dioxide production by

Correct AnswerverifiedShow Answer

Sulfide is toxic to respiring organisms,because it can combine with metals present in ________ that serve a critical function in respiration.

Correct AnswerverifiedShow Answer

The Ca cycle is tightly coupled to the

Correct AnswerverifiedShow Answer

Climate scientists are developing methane hydrates to decrease the effects of global warming.

Correct AnswerverifiedShow Answer

Microbial activity generates methylmercury,which is much less toxic than the mercuric ion.

Correct AnswerverifiedShow Answer

What is a characteristic of a deep sea marine cold seep/vent?

Correct AnswerverifiedShow Answer

What would the result be when a soil is supplemented with S⁰?

Correct AnswerverifiedShow Answer

Bacterial oxidation of Fe²⁺ occurs BEST under which environmental condition?

Correct AnswerverifiedShow Answer

The metabolic process of ammonification ________ ammonia.

Correct AnswerverifiedShow Answer

Lysis of marine algae and cyanobacteria releases the major osmoregulatory solute,dimethylsulfoniopropionate (DMSP) ,which is degraded into the most abundant organic S compound in nature,________.

Correct AnswerverifiedShow Answer

Ocean acidification decreases the precipitation of calcium carbonate and thus will probably affect the cycling of Ca and other nutrients in the ocean.

Correct AnswerverifiedShow Answer

Why does the burning of fossil fuels cause an imbalance within the carbon cycle? What is the consequence of this imbalance? Include a diagram of the carbon cycle to illustrate your answer.

Correct AnswerverifiedAnswers should include a diagram similar...View AnswerShow Answer

One important difference between the C,N,and S cycles and the P,Ca,and Si cycles is that

Correct AnswerverifiedShow Answer

Mercury can serve as a transcriptional activator in the regulation of certain genes.

Correct AnswerverifiedShow Answer

Correct Answer
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Both Fe and Ca cycle between insoluble a...
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Answers should include a diagram similar...
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Correct Answer
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Correct Answer
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