Question 1

While rhizobia usually associate with plant roots, nodules can also be formed along the stems of leguminous plants.

Accepted Answer

A) True 
 B)False

Question 2

Plant diversity is generally lower in environments where mycorrhizae are associated with plants due to strong coevolution, which leads to competitive exclusion.

Accepted Answer

A) True 
 B)False

Question 3

What percentage of terrestrial plants are colonized by arbuscular mycorrhizae?

Accepted Answer

A)  10-15% 
B)  25-30% 
C)  50-60% 
D)  70-90% 
A)  10-15% 
B)  25-30% 
C)  50-60% 
D)  70-90%

Question 4

Symbionts such as Rickettsia in whiteflies and Buchnera in aphids are transmitted ________ to ensure the safe transfer of the symbiont to the next host generation.

Accepted Answer

A)  vertically to offspring 
B)  horizontally through infected water 
C)  horizontally through infected secondary hosts 
D)  vertically through the air 
A)  vertically to offspring 
B)  horizontally through infected water 
C)  horizontally through infected secondary hosts 
D)  vertically through the air

Question 5

Most termites have intracellular symbionts.

Accepted Answer

A) True 
 B)False

Question 6

Ruminants are foregut fermenters.

Accepted Answer

A) True 
 B)False

Question 7

What is the primary difference between a bacteroid a bacterial cell?

Accepted Answer

A)  There are genetic differences that can be detected using 16S rRNA gene sequencing. 
B)  They are biochemically very different from bacterial cells. 
C)  Their cell morphology is different from bacterial morphology. 
D)  They have genetic differences that can be detected using DNA sequencing. 
A)  There are genetic differences that can be detected using 16S rRNA gene sequencing. 
B)  They are biochemically very different from bacterial cells. 
C)  Their cell morphology is different from bacterial morphology. 
D)  They have genetic differences that can be detected using DNA sequencing.

Question 8

Lichens are a mutualistic association of a fungus and either an alga or a cyanobacterium in which

Accepted Answer

A)  the fungus protects the photosynthetic partner from erosion. 
B)  the fungus slowly engulfs the photosynthetic partner. 
C)  the fungus helps collect sunlight for the photosynthetic partner. 
D)  the phototroph provides phosphorus to the fungus. 
A)  the fungus protects the photosynthetic partner from erosion. 
B)  the fungus slowly engulfs the photosynthetic partner. 
C)  the fungus helps collect sunlight for the photosynthetic partner. 
D)  the phototroph provides phosphorus to the fungus.

Question 9

The reproductive systems of many insects can be manipulated by parasitic symbionts, which are passed down to each generation and can skew the sex ratio of their progeny.

Accepted Answer

A) True 
 B)False

Question 10

Consortia of a phototrophic green sulfur bacteria and motile heterotrophs are found worldwide in freshwater stratified sulfidic lakes.

Accepted Answer

A) True 
 B)False

Question 11

The termite hindgut is

Accepted Answer

A)  entirely oxic. 
B)  entirely anoxic. 
C)  variable in oxygen concentration, with distinct microbial niches maintained by patterns of microbial oxygen consumption. 
D)  entirely oxic or entirely anoxic depending upon the diet of the termite. 
A)  entirely oxic. 
B)  entirely anoxic. 
C)  variable in oxygen concentration, with distinct microbial niches maintained by patterns of microbial oxygen consumption. 
D)  entirely oxic or entirely anoxic depending upon the diet of the termite.

Question 12

How are root nodule and arbuscular mycorrhizal symbioses similar?

Accepted Answer

A)  They both use lipochitin oligosaccharide signaling factors to initiate root colonization. 
B)  They both supply nitrogen to the host plant through nitrogen fixation. 
C)  They both increase absorption of nutrients from soil. 
D)  They are both required for the growth and reproduction of their host plants. 
A)  They both use lipochitin oligosaccharide signaling factors to initiate root colonization. 
B)  They both supply nitrogen to the host plant through nitrogen fixation. 
C)  They both increase absorption of nutrients from soil. 
D)  They are both required for the growth and reproduction of their host plants.

Question 13

Lichens always consist of a cyanobacterium and a fungus.

Accepted Answer

A) True 
 B)False

Question 14

Leguminous plants such as alfalfa, beans, clover, peas, and soybeans all benefit from symbiotic bacteria that leach vitamins into their roots.

Accepted Answer

A) True 
 B)False

Question 15

What is the role of the vir genes on a Ti plasmid?

Accepted Answer

A)  to cause crow gall disease (virulence) 
B)  to confer resistance to viral infection 
C)  to initiate replication of the plasmid 
D)  to allow T-DNA transfer 
A)  to cause crow gall disease (virulence) 
B)  to confer resistance to viral infection 
C)  to initiate replication of the plasmid 
D)  to allow T-DNA transfer

Question 16

What is the difference between a primary and secondary insect symbiont? Propose how you might use an insect symbiont to control the spread of an insect-borne disease.

Accepted Answer

Primary symbionts are microorganisms tha

Question 17

Microbial symbionts that are horizontally transferred show greater genome reduction than those that are heritable.

Accepted Answer

A) True 
 B)False

Question 18

Bacterial symbionts of termite hindguts play a critical role in the termiteʹs

Accepted Answer

A)  reproduction. 
B)  nitrogen metabolism. 
C)  resistance to fungal infection. 
D)  reproduction and nitrogen metabolism. 
A)  reproduction. 
B)  nitrogen metabolism. 
C)  resistance to fungal infection. 
D)  reproduction and nitrogen metabolism.

Question 19

Two main symbionts of termites are ________ and ________.

Accepted Answer

A)  archaea / bacteria 
B)  bacteria / fungi 
C)  bacteria / protists 
D)  fungi / protists 
A)  archaea / bacteria 
B)  bacteria / fungi 
C)  bacteria / protists 
D)  fungi / protists

Question 20

Based on 16S RNA phylogenetic data, what phyla are important in the ruminant gut? Give an example of how diet affects ruminant health.

Accepted Answer

The phyla that are most heavily represen

Exam 23: Microbial Symbioses

While rhizobia usually associate with plant roots, nodules can also be formed along the stems of leguminous plants.

Plant diversity is generally lower in environments where mycorrhizae are associated with plants due to strong coevolution, which leads to competitive exclusion.

What percentage of terrestrial plants are colonized by arbuscular mycorrhizae?

Symbionts such as Rickettsia in whiteflies and Buchnera in aphids are transmitted ________ to ensure the safe transfer of the symbiont to the next host generation.

Most termites have intracellular symbionts.

Ruminants are foregut fermenters.

What is the primary difference between a bacteroid a bacterial cell?

Lichens are a mutualistic association of a fungus and either an alga or a cyanobacterium in which

The reproductive systems of many insects can be manipulated by parasitic symbionts, which are passed down to each generation and can skew the sex ratio of their progeny.

Consortia of a phototrophic green sulfur bacteria and motile heterotrophs are found worldwide in freshwater stratified sulfidic lakes.

The termite hindgut is

How are root nodule and arbuscular mycorrhizal symbioses similar?

Lichens always consist of a cyanobacterium and a fungus.

Leguminous plants such as alfalfa, beans, clover, peas, and soybeans all benefit from symbiotic bacteria that leach vitamins into their roots.

What is the role of the vir genes on a Ti plasmid?

What is the difference between a primary and secondary insect symbiont? Propose how you might use an insect symbiont to control the spread of an insect-borne disease.

Microbial symbionts that are horizontally transferred show greater genome reduction than those that are heritable.

Bacterial symbionts of termite hindguts play a critical role in the termiteʹs

Two main symbionts of termites are ________ and ________.

Based on 16S RNA phylogenetic data, what phyla are important in the ruminant gut? Give an example of how diet affects ruminant health.

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

Functional 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 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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Two main symbionts of termites are and .