Question 1

Which term represents the region of soil influenced by plant roots?

Accepted Answer

A)  stele 
B)  cortex 
C)  root cap 
D)  rhizoplane 
E)  rhizosphere 
A)  stele 
B)  cortex 
C)  root cap 
D)  rhizoplane 
E)  rhizosphere

Question 2

Which of the following plays an important role in keeping the water column clear enough for the penetration of light?

Accepted Answer

A)  algae 
B)  bacteria 
C)  fish 
D)  invertebrates 
E)  viruses 
A)  algae 
B)  bacteria 
C)  fish 
D)  invertebrates 
E)  viruses

Question 3

What does the following rarefaction curve NOT suggest about the samples?

Accepted Answer

A)  More soil sequences were collected. 
B)  Indoor air samples appear to be sequenced at enough depth. 
C)  Water samples were not sequenced at enough depth. 
D)  More sequencing should be done for these samples. 
E)  Soil samples were not sequenced at enough depth. 
A)  More soil sequences were collected. 
B)  Indoor air samples appear to be sequenced at enough depth. 
C)  Water samples were not sequenced at enough depth. 
D)  More sequencing should be done for these samples. 
E)  Soil samples were not sequenced at enough depth.

Question 4

Compare and contrast the photic zones of freshwater lake and pelagic ecosystems.

Accepted Answer

The photic zone in the marine habitat is

Question 5

Bacteria found growing in between crystals of solid bedrock as deep as 3 km below Earth's surface are called

Accepted Answer

A)  endophytes. 
B)  symbionts. 
C)  endoliths. 
D)  decomposers. 
E)  saprophytes. 
A)  endophytes. 
B)  symbionts. 
C)  endoliths. 
D)  decomposers. 
E)  saprophytes.

Question 6

In wetlands, Beggiatoa oxidize H₂S for energy. Removal of H₂S enables growth of other microbes for which H₂S is toxic. However, Beggiatoa derives no benefit from these microbes. This interaction is an example of

Accepted Answer

A)  syntrophy. 
B)  mutualism. 
C)  commensalism. 
D)  amensalism. 
E)  synergism. 
A)  syntrophy. 
B)  mutualism. 
C)  commensalism. 
D)  amensalism. 
E)  synergism.

Question 7

The relationship among endosymbiotic microbes in the termite gut that results in complex metabolic fluxes with a negative DG, which would NOT happen for individual members, is called

Accepted Answer

A)  mutualism. 
B)  parasitism. 
C)  exothermic association. 
D)  predation. 
E)  syntrophy. 
A)  mutualism. 
B)  parasitism. 
C)  exothermic association. 
D)  predation. 
E)  syntrophy.

Question 8

Eutrophic lakes typically support ten times the microbial concentrations of an oligotrophic lake. Which of the following statements is NOT true of eutrophic lakes?

Accepted Answer

A)  Biochemical oxygen demand is high. 
B)  Population of aquatic animals is high. 
C)  Nitrogen and phosphorous levels are usually high. 
D)  Photosynthetic activities are altered. 
E)  Algal blooms are common. 
A)  Biochemical oxygen demand is high. 
B)  Population of aquatic animals is high. 
C)  Nitrogen and phosphorous levels are usually high. 
D)  Photosynthetic activities are altered. 
E)  Algal blooms are common.

Question 9

The availability of oxygen and other electron acceptors is the most important determinant of the types of metabolism in a habitat. Which of the following is NOT true about anaerobic environments?

Accepted Answer

A)  They have slower rates of assimilation compared to aerobic habitats. 
B)  Their rates of dissimilation are slower compared to aerobic environments. 
C)  Microbes sometimes use minerals such as NO₂- to oxidize organic compounds. 
D)  Anaerobic microbial biomass far exceeds that of the oxygenated biosphere. 
E)  Respiration of organic compounds is highly dissimilatory, reducing them to CO₂. 
A)  They have slower rates of assimilation compared to aerobic habitats. 
B)  Their rates of dissimilation are slower compared to aerobic environments. 
C)  Microbes sometimes use minerals such as NO₂- to oxidize organic compounds. 
D)  Anaerobic microbial biomass far exceeds that of the oxygenated biosphere. 
E)  Respiration of organic compounds is highly dissimilatory, reducing them to CO₂.

Question 10

All of the following are likely to be found among the benthic microbes EXCEPT

Accepted Answer

A)  barophiles. 
B)  psychrophiles. 
C)  thermophiles. 
D)  phototrophs. 
E)  methanogens. 
A)  barophiles. 
B)  psychrophiles. 
C)  thermophiles. 
D)  phototrophs. 
E)  methanogens.

Question 11

In the legume-rhizobium symbiosis, nitrogen fixation is carried out in nodules by

Accepted Answer

A)  bacteroids that lack a cell wall. 
B)  intact rhizobia in the plant cortex. 
C)  plant cells in the presence of symbiotic bacteria. 
D)  bacteroids in oxygen-rich nodules. 
E)  photosynthetic bacteroids in plants. 
A)  bacteroids that lack a cell wall. 
B)  intact rhizobia in the plant cortex. 
C)  plant cells in the presence of symbiotic bacteria. 
D)  bacteroids in oxygen-rich nodules. 
E)  photosynthetic bacteroids in plants.

Question 12

What is coral bleaching? What is its possible cause?

Accepted Answer

Coral bleaching occurs when coral zooxan

Question 13

The flame-like vertical forms and breakaway pieces of mat in ice-covered Antarctic lakes are caused by

Accepted Answer

A)  limited light penetration in the lake. 
B)  denitrification. 
C)  sulfur-reducing bacteria. 
D)  oxygen production. 
E)  freeze-thaw cycles. 
A)  limited light penetration in the lake. 
B)  denitrification. 
C)  sulfur-reducing bacteria. 
D)  oxygen production. 
E)  freeze-thaw cycles.

Question 14

A holobiont is defined as an

Accepted Answer

A)  organism that benefits while providing no benefit or a hidden benefit to its host. 
B)  interaction that harms one partner nonspecifically without an intimate symbiosis. 
C)  organism that forms an intimate relationship with another, where both benefit. 
D)  entity composed of multiple types of organisms, including microbes. 
E)  intimate relationship in which one member benefits while harming a host. 
A)  organism that benefits while providing no benefit or a hidden benefit to its host. 
B)  interaction that harms one partner nonspecifically without an intimate symbiosis. 
C)  organism that forms an intimate relationship with another, where both benefit. 
D)  entity composed of multiple types of organisms, including microbes. 
E)  intimate relationship in which one member benefits while harming a host.

Question 15

One of the most important ecological roles of the Florida Everglades is that

Accepted Answer

A)  it is home to beautiful birds. 
B)  it filters much of the water supply for Florida communities. 
C)  many bacteria reside in it. 
D)  nutrients can easily be leached to the lakes. 
E)  tourists come to see it in large numbers. 
A)  it is home to beautiful birds. 
B)  it filters much of the water supply for Florida communities. 
C)  many bacteria reside in it. 
D)  nutrients can easily be leached to the lakes. 
E)  tourists come to see it in large numbers.

Question 16

Which of the following organisms forms a specific mutualistic association with legumes?

Accepted Answer

A)  rhizobia 
B)  agrobacteria 
C)  E. coli 
D)  morels 
E)  Vibrio sp. 
A)  rhizobia 
B)  agrobacteria 
C)  E. coli 
D)  morels 
E)  Vibrio sp.

Question 17

The instrument shown in step 5 of the figure below is used for what metagenomics step?

Accepted Answer

A)  DNA isolation 
B)  DNA sequencing 
C)  sample filtering 
D)  cell lysis 
E)  sequence assembly 
A)  DNA isolation 
B)  DNA sequencing 
C)  sample filtering 
D)  cell lysis 
E)  sequence assembly

Question 18

Nonphotosynthetic ________ provide minerals and protection for lichen symbiotic partners.

Accepted Answer

A)  plankton 
B)  proteobacteria 
C)  algae 
D)  fungi 
E)  cyanobacteria 
A)  plankton 
B)  proteobacteria 
C)  algae 
D)  fungi 
E)  cyanobacteria

Question 19

How do metatranscriptomics and metaproteomics address functional limitations of metagenomics?

Accepted Answer

Metatranscriptomics, the study of the RN

Question 20

Describe the initiation process for legume-rhizobium symbiosis.

Accepted Answer

The legume exudes signaling molecules ca

Exam 21: Microbial Ecology

Which term represents the region of soil influenced by plant roots?

Which of the following plays an important role in keeping the water column clear enough for the penetration of light?

What does the following rarefaction curve NOT suggest about the samples?

Compare and contrast the photic zones of freshwater lake and pelagic ecosystems.

Bacteria found growing in between crystals of solid bedrock as deep as 3 km below Earth's surface are called

In wetlands, Beggiatoa oxidize H₂S for energy. Removal of H₂S enables growth of other microbes for which H₂S is toxic. However, Beggiatoa derives no benefit from these microbes. This interaction is an example of

The relationship among endosymbiotic microbes in the termite gut that results in complex metabolic fluxes with a negative DG, which would NOT happen for individual members, is called

Eutrophic lakes typically support ten times the microbial concentrations of an oligotrophic lake. Which of the following statements is NOT true of eutrophic lakes?

The availability of oxygen and other electron acceptors is the most important determinant of the types of metabolism in a habitat. Which of the following is NOT true about anaerobic environments?

All of the following are likely to be found among the benthic microbes EXCEPT

In the legume-rhizobium symbiosis, nitrogen fixation is carried out in nodules by

What is coral bleaching? What is its possible cause?

The flame-like vertical forms and breakaway pieces of mat in ice-covered Antarctic lakes are caused by

A holobiont is defined as an

One of the most important ecological roles of the Florida Everglades is that

Which of the following organisms forms a specific mutualistic association with legumes?

The instrument shown in step 5 of the figure below is used for what metagenomics step?

Nonphotosynthetic ________ provide minerals and protection for lichen symbiotic partners.

How do metatranscriptomics and metaproteomics address functional limitations of metagenomics?

Describe the initiation process for legume-rhizobium symbiosis.

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

Microbes in Global Elemental Cycles

Human Microbiota and Innate Immunity

The Adaptive Immune Response

Microbial Pathogenesis

Microbial Diseases

Antimicrobial Therapy

Clinical Microbiology and Epidemiology

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