Question 1

Unicellular cyanobacteria are the most abundant phototrophs in the ocean and perform 80% of marine photosynthesis.

Accepted Answer

A) True 
 B)False  TRUE

Question 2

Although Cyanobacteria contribute more than 35% of all photosynthesis on Earth, they are not visible in the natural environment.

Accepted Answer

A) True 
 B)False  FALSE

Question 3

The phylogenetic trees of the nifH and SSU rRNA genes of nitrogen-fixing bacteria are incongruent because

Accepted Answer

A)  nitrogenase is an anaerobic enzyme. 
B)  this is a characteristic of all enzyme genes. 
C)  of horizontal gene transfer. 
D)  very few microbes have the nifH gene. 
A)  nitrogenase is an anaerobic enzyme. 
B)  this is a characteristic of all enzyme genes. 
C)  of horizontal gene transfer. 
D)  very few microbes have the nifH gene. C

Question 4

What microbes have a symbiotic association with mussels, living in their gill tissue?

Accepted Answer

A)  methanotrophs 
B)  iron-oxidizing bacteria 
C)  bioluminescent bacteria 
D)  sulfur oxidizing bacteria 
A)  methanotrophs 
B)  iron-oxidizing bacteria 
C)  bioluminescent bacteria 
D)  sulfur oxidizing bacteria

Question 5

Which of the following functional groups form symbiotic relationships with Eukaryotes in deep sea environments?

Accepted Answer

A)  dissimilatory iron-oxidizers 
B)  methanotrophs 
C)  sulfide-oxidizers 
D)  methanotrophs and sulfide-oxidizers 
A)  dissimilatory iron-oxidizers 
B)  methanotrophs 
C)  sulfide-oxidizers 
D)  methanotrophs and sulfide-oxidizers

Question 6

Design an enrichment strategy for the isolation of a heterotrophic sulfate-reducer that could help clean up the oil spill in the sediments of the Gulf of Mexico.

Accepted Answer

To enrich for heterotrophic sulfate-redu

Question 7

Diazotrophs are found in all three domains of life.

Accepted Answer

A) True 
 B)False

Question 8

Thioploca species contain large vacuoles that store ________, which is used to ________ under anaerobic conditions.

Accepted Answer

A)  nitrate / oxidize sulfide 
B)  oxygen / oxidize sulfur 
C)  sulfur / reduce nitrate 
D)  glycogen / provide energy 
A)  nitrate / oxidize sulfide 
B)  oxygen / oxidize sulfur 
C)  sulfur / reduce nitrate 
D)  glycogen / provide energy

Question 9

In which of the following environments would you expect to find a high number of iron-reducing bacteria?

Accepted Answer

A)  acidic mine drainage 
B)  deep subsurface 
C)  open ocean 
D)  agriculture soil 
A)  acidic mine drainage 
B)  deep subsurface 
C)  open ocean 
D)  agriculture soil

Question 10

Sulfide oxidizers are among the most ecologically diverse trophic groups because of the different strategies they employ to access sufficient amounts of sulfide and oxygen simultaneously.

Accepted Answer

A) True 
 B)False

Question 11

Epibiotic predators

Accepted Answer

A)  obtain nutrients by attaching to the surface of prey. 
B)  invade the cytoplasm of their prey. 
C)  invade the periplasmic space of their prey. 
D)  find prey using swarming behavior. 
A)  obtain nutrients by attaching to the surface of prey. 
B)  invade the cytoplasm of their prey. 
C)  invade the periplasmic space of their prey. 
D)  find prey using swarming behavior.

Question 12

Sulfate-reducing bacteria are a ________ that are found in ________ environments.

Accepted Answer

A)  monophyletic group / anoxic 
B)  polyphyletic group / oxic 
C)  morphologically distinct group / anoxic 
D)  morphologically distinct group / oxic 
A)  monophyletic group / anoxic 
B)  polyphyletic group / oxic 
C)  morphologically distinct group / anoxic 
D)  morphologically distinct group / oxic

Question 13

Which of the following functional groups would you expect to find in aerobic iron- and sulfur-rich acidic mine drainage?

Accepted Answer

A)  dissimilative iron-oxidizers 
B)  dissimilative iron-reducers 
C)  purple sulfur bacteria 
D)  purple sulfur bacteria and dissimilative iron-reducers 
A)  dissimilative iron-oxidizers 
B)  dissimilative iron-reducers 
C)  purple sulfur bacteria 
D)  purple sulfur bacteria and dissimilative iron-reducers

Question 14

Budding is a form of reproduction whereby prokaryotic microbes can reproduce sexually.

Accepted Answer

A) True 
 B)False

Question 15

Nitrogenase is a critical enzyme in the nitrogen cycle because it catalyzes the

Accepted Answer

A)  assimilation of ammonia. 
B)  dissimilative reduction of nitrate to nitrogen gas. 
C)  fixation of nitrogen gas into ammonia. 
D)  oxidation of nitrogen gas into nitrate. 
A)  assimilation of ammonia. 
B)  dissimilative reduction of nitrate to nitrogen gas. 
C)  fixation of nitrogen gas into ammonia. 
D)  oxidation of nitrogen gas into nitrate.

Question 16

All phototrophic bacteria use a monophyletic photosystem in photosynthesis, thus there is intense competition for light between different phototrophic bacteria.

Accepted Answer

A) True 
 B)False

Question 17

Diazotrophs are obligately symbiotic bacteria that fix N₂ into ammonia, thus providing a critical source of nitrogen to their host.

Accepted Answer

A) True 
 B)False

Question 18

Diazotrophs maximize nitrogenase activity by

Accepted Answer

A)  closely coupling N₂ fixation with high rates of photosynthesis. 
B)  fixing N₂ at times when oxygen is absent or in low concentrations. 
C)  producing specialized structures to protect nitrogenase from oxygen. 
D)  producing specialized structures or fixing N₂ at times when oxygen is absent to protect nitrogenase from oxygen. 
A)  closely coupling N₂ fixation with high rates of photosynthesis. 
B)  fixing N₂ at times when oxygen is absent or in low concentrations. 
C)  producing specialized structures to protect nitrogenase from oxygen. 
D)  producing specialized structures or fixing N₂ at times when oxygen is absent to protect nitrogenase from oxygen.

Question 19

Budding bacteria form new cell wall material at a single point rather than throughout the whole cell.

Accepted Answer

A) True 
 B)False

Question 20

Typical electron donors used by dissimilative sulfate-reducers are

Accepted Answer

A)  hydrogen, water, and hyrdrogen sulfide. 
B)  hydrogen, lactate, and pyruvate. 
C)  carbon dioxide, hydrogen, and water. 
D)  sulfate, sulfur, and thiosulfate. 
A)  hydrogen, water, and hyrdrogen sulfide. 
B)  hydrogen, lactate, and pyruvate. 
C)  carbon dioxide, hydrogen, and water. 
D)  sulfate, sulfur, and thiosulfate.

Exam 15: Functional Diversity of Microorganisms

Unicellular cyanobacteria are the most abundant phototrophs in the ocean and perform 80% of marine photosynthesis.

Although Cyanobacteria contribute more than 35% of all photosynthesis on Earth, they are not visible in the natural environment.

The phylogenetic trees of the nifH and SSU rRNA genes of nitrogen-fixing bacteria are incongruent because

What microbes have a symbiotic association with mussels, living in their gill tissue?

Which of the following functional groups form symbiotic relationships with Eukaryotes in deep sea environments?

Design an enrichment strategy for the isolation of a heterotrophic sulfate-reducer that could help clean up the oil spill in the sediments of the Gulf of Mexico.

Diazotrophs are found in all three domains of life.

Thioploca species contain large vacuoles that store ________, which is used to ________ under anaerobic conditions.

In which of the following environments would you expect to find a high number of iron-reducing bacteria?

Sulfide oxidizers are among the most ecologically diverse trophic groups because of the different strategies they employ to access sufficient amounts of sulfide and oxygen simultaneously.

Epibiotic predators

Sulfate-reducing bacteria are a ________ that are found in ________ environments.

Which of the following functional groups would you expect to find in aerobic iron- and sulfur-rich acidic mine drainage?

Budding is a form of reproduction whereby prokaryotic microbes can reproduce sexually.

Nitrogenase is a critical enzyme in the nitrogen cycle because it catalyzes the

All phototrophic bacteria use a monophyletic photosystem in photosynthesis, thus there is intense competition for light between different phototrophic bacteria.

Diazotrophs are obligately symbiotic bacteria that fix N₂ into ammonia, thus providing a critical source of nitrogen to their host.

Diazotrophs maximize nitrogenase activity by

Budding bacteria form new cell wall material at a single point rather than throughout the whole cell.

Typical electron donors used by dissimilative sulfate-reducers are

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

Filters

Thioploca species contain large vacuoles that store , which is used to under anaerobic conditions.

Sulfate-reducing bacteria are a that are found in environments.