Question 1

The only group of oxygenic phototrophic bacteria are the

Accepted Answer

A)  green nonsulfur bacteria. 
B)  Chloroflexi. 
C)  Cyanobacteria. 
D)  Chlorobi. 
A)  green nonsulfur bacteria. 
B)  Chloroflexi. 
C)  Cyanobacteria. 
D)  Chlorobi.

Question 2

What is convergent evolution and how is it different from horizontal gene transfer?

Accepted Answer

Convergent evolution is the evolution of

Question 3

Green sulfur bacteria are often found at the greatest depths of all phototrophic cells in lakes, oceans, and microbial mats. This is because green sulfur bacteria

Accepted Answer

A)  are very sensitive to UV irradiation, despite their reliance on light for energy. 
B)  are the only phototrophs that can use hydrogen sulfide as an electron donor for photosynthesis. 
C)  are strict anaerobes. 
D)  have chlorosomes that are very efficient at harvesting light, allowing them to perform photosynthesis where light intensities are very low. 
A)  are very sensitive to UV irradiation, despite their reliance on light for energy. 
B)  are the only phototrophs that can use hydrogen sulfide as an electron donor for photosynthesis. 
C)  are strict anaerobes. 
D)  have chlorosomes that are very efficient at harvesting light, allowing them to perform photosynthesis where light intensities are very low.

Question 4

Most methanotrophs are obligate ________ because ________.

Accepted Answer

A)  aerobes / the initial step of methane oxidation requires O₂ 
B)  anaerobes / methane is produced in anaerobic environments 
C)  fermenters / methane only provides enough energy for fermentation 
D)  heterotrophs / methane does not provide enough carbon for growth 
A)  aerobes / the initial step of methane oxidation requires O₂ 
B)  anaerobes / methane is produced in anaerobic environments 
C)  fermenters / methane only provides enough energy for fermentation 
D)  heterotrophs / methane does not provide enough carbon for growth

Question 5

How are anoxygenic phototrophic microorganisms more physiologically diverse than oxygenic phototrophic microorganisms? Be specific in your answers and use examples to illustrate your conclusions.

Accepted Answer

Oxygenic phototrophs (Cyanobacteria) are

Question 6

You are looking at a sample from the top green layer of a colorful bacterial mat. Using phase contrast and fluorescence microscopy, you see evenly spaced cells in the middle of a filament that are slightly smaller than the others. The smaller cells are not fluorescent, indicating they lack photosystem II, but the rest of the filament is fluorescent. What type of filamentous bacteria are you most likely looking at?

Accepted Answer

A)  purple nonsulfur bacteria 
B)  green sulfur bacteria 
C)  Acidobacteria 
D)  Cyanobacteria 
A)  purple nonsulfur bacteria 
B)  green sulfur bacteria 
C)  Acidobacteria 
D)  Cyanobacteria

Question 7

Given that multiple diverse phyla (e.g., diverse phylogenetic groups) of microorganisms can perform similar functions in ecosystems, how we might predict the microbial functions performed by a particular organism or in a particular environment without relying on growing all of the microbes in the lab?

Accepted Answer

Without growing all of the microbes in t

Question 8

Bacteria that contain complex internal membrane systems are more likely to divide by budding than by binary fission.

Accepted Answer

A) True 
 B)False

Question 9

All microbial phototrophs

Accepted Answer

A)  fix carbon dioxide. 
B)  use water as an electron donor for photosynthesis. 
C)  fix carbon dioxide and use water as an electron donor for photosynthesis. 
D)  use light energy to drive electron transport to generate energy. 
A)  fix carbon dioxide. 
B)  use water as an electron donor for photosynthesis. 
C)  fix carbon dioxide and use water as an electron donor for photosynthesis. 
D)  use light energy to drive electron transport to generate energy.

Question 10

How do Cyanobacteria impact the ecology of both aquatic and terrestrial environments on Earth?

Accepted Answer

Cyanobacteria can contribute up to 80% o

Question 11

Dissimilative iron-reducing bacteria couple which oxidation-reduction reactions?

Accepted Answer

A)  The reduction of ferric iron or manganese and the oxidation of sulfur. 
B)  The reduction of ferric iron or manganese and the fermentation of sugars. 
C)  The oxidation of H₂ or organic compounds and the reduction of ferric iron or manganese. 
D)  The reduction of ferric iron and photosynthesis. 
A)  The reduction of ferric iron or manganese and the oxidation of sulfur. 
B)  The reduction of ferric iron or manganese and the fermentation of sugars. 
C)  The oxidation of H₂ or organic compounds and the reduction of ferric iron or manganese. 
D)  The reduction of ferric iron and photosynthesis.

Question 12

Thiobacillus species are acidophilic chemolithotrophs capable of autotrophic growth. They perform the dissimilative oxidation of H₂S, Sᵒ, thiosulfate, or Fe⁺². Diagram or explain how Thiobacillus species obtain carbon and energy for growth and predict what type of environment they would be found in.

Accepted Answer

Thiobacillus species obtain carbon for g

Question 13

Myxobacteria display ________ behavior and form ________ that produce myxospores.

Accepted Answer

A)  gliding / slime trails 
B)  chemotactic / colonies 
C)  phototactic / slime trails 
D)  swarming / fruiting bodies 
A)  gliding / slime trails 
B)  chemotactic / colonies 
C)  phototactic / slime trails 
D)  swarming / fruiting bodies

Question 14

Dissimilatory sulfide-oxidizers use a variety of unique ecological strategies in order to

Accepted Answer

A)  avoid the toxicity of hydrogen sulfide. 
B)  position themselves at interfaces where sulfide and oxygen meet. 
C)  position themselves where there is sufficient light for sulfide oxidation. 
D)  find organic carbon substrates. 
A)  avoid the toxicity of hydrogen sulfide. 
B)  position themselves at interfaces where sulfide and oxygen meet. 
C)  position themselves where there is sufficient light for sulfide oxidation. 
D)  find organic carbon substrates.

Question 15

Dissimilatory nitrate reduction results in the production of gaseous products, while assimilatory nitrate reduction results in the production of ammonia for biosynthesis.

Accepted Answer

A) True 
 B)False

Question 16

What form of photosynthesis evolved first on Earth?

Accepted Answer

A)  oxygenic 
B)  anoxygenic 
C)  autotrophic 
D)  heterotrophic 
A)  oxygenic 
B)  anoxygenic 
C)  autotrophic 
D)  heterotrophic

Question 17

What is one especially unique characteristic of methanotrophs?

Accepted Answer

A)  They metabolize H2S. 
B)  They have unusually large amounts of sterols. 
C)  They can exist as consortia. 
D)  They are capable of bioluminescence. 
A)  They metabolize H2S. 
B)  They have unusually large amounts of sterols. 
C)  They can exist as consortia. 
D)  They are capable of bioluminescence.

Question 18

Discuss the ecological importance of the enzyme nitrogenase, the diversity and physiology of the various groups of organisms that contain it, and the strategies these organisms use to optimize conditions for the enzyme.

Accepted Answer

The enzyme nitrogenase is the only enzym

Question 19

What growth conditions would you use to enrich for ammonia-oxidizing bacteria?

Accepted Answer

A)  aerobic mineral media with ammonia and bicarbonate incubated in the dark 
B)  anaerobic mineral media with acetate and ammonia incubated in the dark 
C)  aerobic mineral media with acetate and ammonia incubated in the dark 
D)  anaerobic mineral media with ammonia and nitrate incubated in the dark 
A)  aerobic mineral media with ammonia and bicarbonate incubated in the dark 
B)  anaerobic mineral media with acetate and ammonia incubated in the dark 
C)  aerobic mineral media with acetate and ammonia incubated in the dark 
D)  anaerobic mineral media with ammonia and nitrate incubated in the dark

Question 20

Bioluminescence is controlled by the gene regulatory mechanism called quorum sensing, wherein the

Accepted Answer

A)  depletion of oxygen is detected by an inducer molecule which activates transcription of the lux operon (genes luxCDAB
E) . 
B)  accumulation of an inducer molecule activates transcription of the lux operon (genes luxCDAB
E) . 
C)  absence of light activates an inducer molecule which activates transcription of the lux operon (genes luxCDAB
E) . 
D)  host tissues produce an autoinducer molecule which activates transcription of the lux operon (genes luxCDAB
E) . 
A)  depletion of oxygen is detected by an inducer molecule which activates transcription of the lux operon (genes luxCDAB
E) . 
B)  accumulation of an inducer molecule activates transcription of the lux operon (genes luxCDAB
E) . 
C)  absence of light activates an inducer molecule which activates transcription of the lux operon (genes luxCDAB
E) . 
D)  host tissues produce an autoinducer molecule which activates transcription of the lux operon (genes luxCDAB
E) .

Exam 15: Functional Diversity of Microorganisms

The only group of oxygenic phototrophic bacteria are the

What is convergent evolution and how is it different from horizontal gene transfer?

Green sulfur bacteria are often found at the greatest depths of all phototrophic cells in lakes, oceans, and microbial mats. This is because green sulfur bacteria

Most methanotrophs are obligate ________ because ________.

How are anoxygenic phototrophic microorganisms more physiologically diverse than oxygenic phototrophic microorganisms? Be specific in your answers and use examples to illustrate your conclusions.

Bacteria that contain complex internal membrane systems are more likely to divide by budding than by binary fission.

All microbial phototrophs

How do Cyanobacteria impact the ecology of both aquatic and terrestrial environments on Earth?

Dissimilative iron-reducing bacteria couple which oxidation-reduction reactions?

Myxobacteria display ________ behavior and form ________ that produce myxospores.

Dissimilatory sulfide-oxidizers use a variety of unique ecological strategies in order to

Dissimilatory nitrate reduction results in the production of gaseous products, while assimilatory nitrate reduction results in the production of ammonia for biosynthesis.

What form of photosynthesis evolved first on Earth?

What is one especially unique characteristic of methanotrophs?

Discuss the ecological importance of the enzyme nitrogenase, the diversity and physiology of the various groups of organisms that contain it, and the strategies these organisms use to optimize conditions for the enzyme.

What growth conditions would you use to enrich for ammonia-oxidizing bacteria?

Bioluminescence is controlled by the gene regulatory mechanism called quorum sensing, wherein the

The Microbial World

Microbial Cell Structure and Function

Microbial Metabolism

Molecular Information Flow and Protein Processing

Microbial Growth and Its Control

Microbial Regulatory Systems

Molecular Biology of Microbial Growth

Viruses and Their Replication

Microbial Systems Biology

Viral Genomics, Diversity, and Ecology

Genetics of Bacteria and Archaea

Biotechnology and Synthetic Biology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Diversity of Bacteria

Diversity of Archaea

Diversity of Microbial Eukarya

Taking the Measure of Microbial Systems

Microbial Ecosystems

Nutrient Cycles

Microbiology of the Built Environment

Microbial Symbioses

Microbial Symbioses with Humans

Microbial Infection and Pathogenesis

Innate Immunity: Broadly Specific Host Defenses

Adaptive Immunity: Highly Specific Host Defenses

Clinical Microbiology and Immunology

Epidemiology

Person-to-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Waterborne and Foodborne Bacterial and Viral Diseases

Eukaryotic Pathogens: Fungi, Protozoans, and Helminths

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Most methanotrophs are obligate because .

Myxobacteria display behavior and form that produce myxospores.