Question 1

Calcium is cycled most rapidly in terrestrial environments.

Accepted Answer

A) True 
 B)False

Question 2

Energy yields are high enough for Fe²⁺ oxidation that the bacteria that perform this reaction require only small quantities of Fe²⁺ to be available.

Accepted Answer

A) True 
 B)False

Question 3

Diatoms require silica due to their

Accepted Answer

A)  Ca²⁺/Si⁴⁺ symporters. 
B)  DNA replication mechanism. 
C)  ornate frustules. 
D)  unique phototrophic physiology. 
A)  Ca²⁺/Si⁴⁺ symporters. 
B)  DNA replication mechanism. 
C)  ornate frustules. 
D)  unique phototrophic physiology.

Question 4

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)  cytochromes 
A)  glycolysis enzymes 
B)  oxidases 
C)  NADH 
D)  cytochromes

Question 5

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. 
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.

Question 6

The largest reservoir of methane is found

Accepted Answer

A)  as methane hydrates trapped under permafrost and marine sediments. 
B)  in the rumen of cows and other ruminant animals. 
C)  in the atmosphere in gaseous form. 
D)  trapped in volcanic rocks in tropical environments around the world. 
A)  as methane hydrates trapped under permafrost and marine sediments. 
B)  in the rumen of cows and other ruminant animals. 
C)  in the atmosphere in gaseous form. 
D)  trapped in volcanic rocks in tropical environments around the world.

Question 7

Which of the following is a sulfide?

Accepted Answer

A)  H₂S 
B)  HS⁻ 
C)  S²⁻ 
D)  H₂S, HS⁻, and S²⁻ are all sulfides. 
A)  H₂S 
B)  HS⁻ 
C)  S²⁻ 
D)  H₂S, HS⁻, and S²⁻ are all sulfides.

Question 8

Mercury has both organic and inorganic forms that are neurotoxic.

Accepted Answer

A) True 
 B)False

Question 9

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 sulfite 
A)  dimethyl sulfide production due to mixotrophs 
B)  organic carbon production due to anaerobes 
C)  soil acidification due to chemolithotrophs 
D)  syntrophic utilization of sulfite

Question 10

Nitrification and anammox both

Accepted Answer

A)  create nitrogen gas, but nitrification is aerobic while anammox is anaerobic. 
B)  oxidize ammonia, but nitrification uses O₂ ₐs ₐn ₑlₑctᵣₒn ₐccₑptₒᵣ and anammox uses NO₂-. 
C)  are aerobic processes, but nitrification produces NO₃- and annamox produces N₂ gas. 
D)  occur in soils at neutral pH. 
A)  create nitrogen gas, but nitrification is aerobic while anammox is anaerobic. 
B)  oxidize ammonia, but nitrification uses O₂ ₐs ₐn ₑlₑctᵣₒn ₐccₑptₒᵣ and anammox uses NO₂-. 
C)  are aerobic processes, but nitrification produces NO₃- and annamox produces N₂ gas. 
D)  occur in soils at neutral pH.

Question 11

Nitrous oxide (N₂O) is a

Accepted Answer

A)  direct product of ammonification. 
B)  direct product ofnitrogen fixation. 
C)  potent greenhouse gas that is a product of nitrification. 
D)  potent greenhouse gas that is a product of denitrification. 
A)  direct product of ammonification. 
B)  direct product ofnitrogen fixation. 
C)  potent greenhouse gas that is a product of nitrification. 
D)  potent greenhouse gas that is a product of denitrification.

Question 12

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 13

Most chemolithotrophic bacteria that oxidize sulfur are aerobes.

Accepted Answer

A) True 
 B)False

Question 14

Abiotic oxidation of Fe²⁺ requires oxygen and occurs rapidly when the pH is near 7.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following is/are NOT a degradation product of organic material?

Accepted Answer

A)  carbon dioxide 
B)  methane 
C)  oxygen 
D)  All of these answer choices are degradation products of organic material. 
A)  carbon dioxide 
B)  methane 
C)  oxygen 
D)  All of these answer choices are degradation products of organic material.

Question 16

The Fe and Mn cycles include

Accepted Answer

A)  reduced and oxidized forms that are very chemically reactive. 
B)  large reservoirs of solid mineral forms that are chemically inert. 
C)  incorporation of Fe and Mn into the exoskeletons of diatoms and other alga. 
D)  toxic forms that can poison aquatic ecosystems if the cycles are imbalanced. 
A)  reduced and oxidized forms that are very chemically reactive. 
B)  large reservoirs of solid mineral forms that are chemically inert. 
C)  incorporation of Fe and Mn into the exoskeletons of diatoms and other alga. 
D)  toxic forms that can poison aquatic ecosystems if the cycles are imbalanced.

Question 17

Syntrophic organisms cannot grow fermentatively without a hydrogen-consuming partner organism.

Accepted Answer

A) True 
 B)False

Question 18

How are the Ca cycle and the C cycle linked in marine environments? How will increased carbon dioxide from anthropogenic activity affect the Ca and C cycling in marine environments?

Accepted Answer

Several eukaryotic phototrophic microorg

Question 19

The calcium 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. 
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.

Question 20

The mercury in fish is normally in the form of elemental mercury (Hg⁰).

Accepted Answer

A) True 
 B)False

Exam 21: Nutrient Cycles

Calcium is cycled most rapidly in terrestrial environments.

Energy yields are high enough for Fe²⁺ oxidation that the bacteria that perform this reaction require only small quantities of Fe²⁺ to be available.

Diatoms require silica due to their

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

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

The largest reservoir of methane is found

Which of the following is a sulfide?

Mercury has both organic and inorganic forms that are neurotoxic.

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

Nitrification and anammox both

Nitrous oxide (N₂O) is a

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.

Most chemolithotrophic bacteria that oxidize sulfur are aerobes.

Abiotic oxidation of Fe²⁺ requires oxygen and occurs rapidly when the pH is near 7.

Which of the following is/are NOT a degradation product of organic material?

The Fe and Mn cycles include

Syntrophic organisms cannot grow fermentatively without a hydrogen-consuming partner organism.

How are the Ca cycle and the C cycle linked in marine environments? How will increased carbon dioxide from anthropogenic activity affect the Ca and C cycling in marine environments?

The calcium cycle is tightly coupled to the

The mercury in fish is normally in the form of elemental mercury (Hg⁰).

The Microbial World

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Molecular Information Flow and Protein Processing

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Taking the Measure of Microbial Systems

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