Question 1

Which of the following is assimilated almost entirely in the oxidized state?

Accepted Answer

A)  sulfur 
B)  nitrogen 
C)  phosphorus 
D)  carbon 
E)  iron 
A)  sulfur 
B)  nitrogen 
C)  phosphorus 
D)  carbon 
E)  iron C

Question 2

On which of the following does humankind expect to find life because of the similarity of its geology to that of Earth?

Accepted Answer

A)  Jupiter 
B)  Venus 
C)  Mars 
D)  Jupiter's moon Europa 
E)  Pluto 
A)  Jupiter 
B)  Venus 
C)  Mars 
D)  Jupiter's moon Europa 
E)  Pluto C

Question 3

Discuss the difference in environmental availability of phosphorus versus sulfur and nitrogen.

Accepted Answer

Unlike sulfur and nitrogen, which are found in several different oxidation states, phosphorus is cycled mainly in the fully oxidized state of phosphate. The absence of fully reduced phosphorus in ecosystems may be due to the fact that reduced phosphorus (phosphine, PH₃) undergoes spontaneous combustion in the presence of oxygen. Some anaerobic decomposers use phosphate as a terminal electron acceptor, reducing it to phosphine. Although phosphate is abundant in Earth's crust, its availability in ecosystems is limited by its tendency to precipitate with calcium, magnesium, and iron ions. Thus, dissolved phosphate in water and soil is often a limiting nutrient for productivity. In natural ecosystems, the available phosphate is taken up rapidly by bacteria and phytoplankton, and then consumed by grazers and predators and dispersed by decomposers.

Question 4

Explain how the Mississippi River drainage into the Gulf of Mexico off the coast of Louisiana leads to a large dead zone.

Accepted Answer

Over its long, meandering course, which

Question 5

Jupiter's moon ________ is a candidate for extraterrestrial life due to its subsurface oceans.

Accepted Answer

A)  Io 
B)  Europa 
C)  Titan 
D)  Mimas 
E)  Deimos 
A)  Io 
B)  Europa 
C)  Titan 
D)  Mimas 
E)  Deimos

Question 6

The largest reservoir for carbon is

Accepted Answer

A)  the atmosphere. 
B)  ocean biomass. 
C)  carbonate rocks and subsurface carbon. 
D)  wetlands. 
E)  fossil fuels. 
A)  the atmosphere. 
B)  ocean biomass. 
C)  carbonate rocks and subsurface carbon. 
D)  wetlands. 
E)  fossil fuels.

Question 7

How did Jill Mikucki test her hypothesis that a subsurface river of brine flows deep beneath the glaciers and permafrost of Taylor Valley, feeding Blood Falls?

Accepted Answer

To gain evidence for this model, Mikucki

Question 8

What types of bacteria will carry out nitrification?

Accepted Answer

A)  lithotrophs 
B)  heterotrophs 
C)  chemoorganotrophy 
D)  phototrophs 
E)  fastidious heterotrophs 
A)  lithotrophs 
B)  heterotrophs 
C)  chemoorganotrophy 
D)  phototrophs 
E)  fastidious heterotrophs

Question 9

Astrobiology is the study of life in the universe. Why might our rDNA probes NOT be appropriate to detect extraterrestrial life?

Accepted Answer

Our rDNA probes were developed based on

Question 10

Eolian sources of iron in marine systems are due to.

Accepted Answer

A)  precipitation of Fe3+ by OH- or PO43-. 
B)  phytoplankton consumers. 
C)  iron-oxidizing bacteria. 
D)  wind-borne dust from dry land. 
E)  reduction of Fe3+ by anaerobic respiration. 
A)  precipitation of Fe3+ by OH- or PO43-. 
B)  phytoplankton consumers. 
C)  iron-oxidizing bacteria. 
D)  wind-borne dust from dry land. 
E)  reduction of Fe3+ by anaerobic respiration.

Question 11

Dinitrogen gas constitutes ________ of the atmosphere.

Accepted Answer

A)  10% 
B)  79% 
C)  69% 
D)  21% 
E)  0.03% 
A)  10% 
B)  79% 
C)  69% 
D)  21% 
E)  0.03%

Question 12

In polluted ocean waters, what type of organisms may contribute significantly to global warming?

Accepted Answer

A)  photosynthetic algae 
B)  methanogens 
C)  vent bacteria 
D)  marine mammals 
E)  denitrifying bacteria 
A)  photosynthetic algae 
B)  methanogens 
C)  vent bacteria 
D)  marine mammals 
E)  denitrifying bacteria

Question 13

The upper region indicated in the figure below is called

Accepted Answer

A)  deep oxycline. 
B)  upwelling zone. 
C)  benthos. 
D)  oxygen minimum zone. 
E)  upper oxycline. 
A)  deep oxycline. 
B)  upwelling zone. 
C)  benthos. 
D)  oxygen minimum zone. 
E)  upper oxycline.

Question 14

If an oligotrophic marine system has low concentrations of both nitrogen and phosphorus, it is said to be

Accepted Answer

A)  eutrophic. 
B)  polluted. 
C)  high BOD. 
D)  colimited. 
E)  hypoxic. 
A)  eutrophic. 
B)  polluted. 
C)  high BOD. 
D)  colimited. 
E)  hypoxic.

Question 15

Which of the following is the most limiting element in marine ecosystems?

Accepted Answer

A)  iron 
B)  sulfur 
C)  carbon 
D)  phosphorous 
E)  hydrogen 
A)  iron 
B)  sulfur 
C)  carbon 
D)  phosphorous 
E)  hydrogen

Question 16

Which of the following spontaneously ignites with a green glow as it emanates from the ground?

Accepted Answer

A)  pyrite 
B)  nitrous oxide 
C)  dimethyl sulfide 
D)  phosphine 
E)  dimethylmercury 
A)  pyrite 
B)  nitrous oxide 
C)  dimethyl sulfide 
D)  phosphine 
E)  dimethylmercury

Question 17

Describe the difference between a source, sink, and reservoir of an element.

Accepted Answer

A location within the biosphere that con

Question 18

What is the cause of the highlighted zone with dissolved oxygen less than 2.0 mg/l?

Accepted Answer

A)  high carbon and nitrogen concentrations 
B)  high iron concentrations 
C)  low oxygen concentrations 
D)  high phosphorus concentrations 
E)  the Deepwater Horizon oil spill 
A)  high carbon and nitrogen concentrations 
B)  high iron concentrations 
C)  low oxygen concentrations 
D)  high phosphorus concentrations 
E)  the Deepwater Horizon oil spill

Question 19

What does the increase in nitrite (NO₂⁻) and nitrous oxide (N₂O) in the following figure indicate? Describe this process in detail.

Accepted Answer

Bacteria and archaea reduce nitrate thro

Question 20

Modifications of ________ structure and composition represents a common microbial adaptation to limiting phosphorous concentrations.

Accepted Answer

A)  membrane 
B)  protein 
C)  DNA 
D)  polysaccharide 
E)  the cell wall 
A)  membrane 
B)  protein 
C)  DNA 
D)  polysaccharide 
E)  the cell wall

Exam 22: Microbes in Global Elemental Cycles

Which of the following is assimilated almost entirely in the oxidized state?

On which of the following does humankind expect to find life because of the similarity of its geology to that of Earth?

Discuss the difference in environmental availability of phosphorus versus sulfur and nitrogen.

Explain how the Mississippi River drainage into the Gulf of Mexico off the coast of Louisiana leads to a large dead zone.

Jupiter's moon ________ is a candidate for extraterrestrial life due to its subsurface oceans.

The largest reservoir for carbon is

How did Jill Mikucki test her hypothesis that a subsurface river of brine flows deep beneath the glaciers and permafrost of Taylor Valley, feeding Blood Falls?

What types of bacteria will carry out nitrification?

Astrobiology is the study of life in the universe. Why might our rDNA probes NOT be appropriate to detect extraterrestrial life?

Eolian sources of iron in marine systems are due to.

Dinitrogen gas constitutes ________ of the atmosphere.

In polluted ocean waters, what type of organisms may contribute significantly to global warming?

The upper region indicated in the figure below is called

If an oligotrophic marine system has low concentrations of both nitrogen and phosphorus, it is said to be

Which of the following is the most limiting element in marine ecosystems?

Which of the following spontaneously ignites with a green glow as it emanates from the ground?

Describe the difference between a source, sink, and reservoir of an element.

What is the cause of the highlighted zone with dissolved oxygen less than 2.0 mg/l?

What does the increase in nitrite (NO₂⁻) and nitrous oxide (N₂O) in the following figure indicate? Describe this process in detail.

Modifications of ________ structure and composition represents a common microbial adaptation to limiting phosphorous concentrations.

Microbial Life: Origin and Discovery

Observing the Microbial Cell

Cell Structure and Function

Bacterial Culture, Growth, and Development

Environmental Influences and Control of Microbial Growth

Viruses

Genomes and Chromosomes

Transcription, Translation, and Bioinformatics

Gene Transfer, Mutations, and Genome Evolution

Molecular Regulation

Viral Molecular Biology

Biotechniques and Synthetic Biology

Energetics and Catabolism

Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

Biosynthesis

Food and Industrial Microbiology

Origins and Evolution

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

Microbial Ecology

Human Microbiota and Innate Immunity

The Adaptive Immune Response

Microbial Pathogenesis

Microbial Diseases

Antimicrobial Therapy

Clinical Microbiology and Epidemiology

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