Question 1

The mutualism of Azolla-Anabaena is useful for

Accepted Answer

A)  aquaculturalists. 
B)  corn farmers. 
C)  rice farmers. 
D)  tropical forest community succession. 
A)  aquaculturalists. 
B)  corn farmers. 
C)  rice farmers. 
D)  tropical forest community succession. C

Question 2

How do arbuscular mycorrhizae (AM) help plants obtain more nutrients from the soil?

Accepted Answer

A)  By-products of AM metabolism serve as primary nutrient sources for the plants. 
B)  The AM increase the total surface area to absorb more nutrients. 
C)  The hyphae develop as specialized nodules that directly produce nutrients for the plant. 
D)  Signaling molecules in the plant are passed to the AM to initiate electron flow, which is in turn used to create ATP. 
A)  By-products of AM metabolism serve as primary nutrient sources for the plants. 
B)  The AM increase the total surface area to absorb more nutrients. 
C)  The hyphae develop as specialized nodules that directly produce nutrients for the plant. 
D)  Signaling molecules in the plant are passed to the AM to initiate electron flow, which is in turn used to create ATP. B

Question 3

Which of the following do dinoflagellates most commonly associate with in a mutualistic relationship?

Accepted Answer

A)  clams 
B)  corals 
C)  flatworms 
D)  snails 
A)  clams 
B)  corals 
C)  flatworms 
D)  snails B

Question 4

What is one reason that acetogenesis is favored over methanogenesis in the termite gut?

Accepted Answer

A)  The environment is anoxic. 
B)  Methanogens can use a wide range of substrates, but acetogens specialize in those produced in the termite gut. 
C)  Methanogens are not found in the termite gut. 
D)  Acetogens are better at colonizing the center of the gut, which is rich in H₂. 
A)  The environment is anoxic. 
B)  Methanogens can use a wide range of substrates, but acetogens specialize in those produced in the termite gut. 
C)  Methanogens are not found in the termite gut. 
D)  Acetogens are better at colonizing the center of the gut, which is rich in H₂.

Question 5

When squids that contain luminescent bacterial symbionts hatch, they do NOT contain a bacterial symbiont. Symbiont transmission in this symbiosis is

Accepted Answer

A)  vertical from parent to offspring. 
B)  horizontal and involves specific selection of the symbiont from the environment. 
C)  random and results in various different species being selected as the symbiont. 
D)  mixed and results in multiple symbiont species colonizing the squid at once. 
A)  vertical from parent to offspring. 
B)  horizontal and involves specific selection of the symbiont from the environment. 
C)  random and results in various different species being selected as the symbiont. 
D)  mixed and results in multiple symbiont species colonizing the squid at once.

Question 6

Gut symbionts are lost after each molting a termite undergoes.

Accepted Answer

A) True 
 B)False

Question 7

Both lichens and corals are symbioses involving phototrophic microorganisms. Compare and contrast lichens and corals, including the types of organisms involved, the role of each partner, the specificity of the interaction, and the method of transmission for each symbiosis.

Accepted Answer

Lichens are found on house roofs, tree t

Question 8

Bacterial cells themselves serve as major sources of protein and vitamins in hindgut fermenting animals such as rabbits and horses.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following is a common benefit of a microbe-plant symbiosis?

Accepted Answer

A)  increased nutrient availability only 
B)  decreased pathogen colonization only 
C)  increased affinity for carbon dioxide 
D)  increased nutrient availability and decreased pathogen colonization 
A)  increased nutrient availability only 
B)  decreased pathogen colonization only 
C)  increased affinity for carbon dioxide 
D)  increased nutrient availability and decreased pathogen colonization

Question 10

The following quote is taken from a university extension publication for farmers:
ʺGrain poisoning, also known as grain overload or lactic acidosis, is usually the result of stock consuming large quantities of grain or pellets to which they are unaccustomed. Pasture-fed cows or feedlot cattle not yet adapted to grain may become acutely ill or die after eating only moderate amounts of grain, whereas stock accustomed to diets high in grain content may consume large amounts of grain with little or no effect.ʺ
What is happening in the digestive system of the livestock that causes grain poisoning and why does a gradual shift in diet avoid this problem?

Accepted Answer

A major shift in diet, where the rumen f

Question 11

The insect symbiont Wolbachia can be used to suppress disease transmission by mosquitoes because

Accepted Answer

A)  Wolbachia supplies essential nutrients to the mosquito Culex quinquefasciatus. 
B)  only Wolbachia-infected mosquitoes can transmit viral diseases such as dengue fever. 
C)  Wolbachia infections can spread rapidly through a mosquito population, killing all the mosquitoes. 
D)  Wolbachia-infected male mosquitoes sterilize uninfected female mosquitoes. 
A)  Wolbachia supplies essential nutrients to the mosquito Culex quinquefasciatus. 
B)  only Wolbachia-infected mosquitoes can transmit viral diseases such as dengue fever. 
C)  Wolbachia infections can spread rapidly through a mosquito population, killing all the mosquitoes. 
D)  Wolbachia-infected male mosquitoes sterilize uninfected female mosquitoes.

Question 12

Secondary symbionts in insects often live

Accepted Answer

A)  inside cells only. 
B)  in hemolymph only. 
C)  inside bacteriocytes only. 
D)  inside cells, in hemolymph, or inside bacteriocytes. 
A)  inside cells only. 
B)  in hemolymph only. 
C)  inside bacteriocytes only. 
D)  inside cells, in hemolymph, or inside bacteriocytes.

Question 13

Frankia are

Accepted Answer

A)  a type of arbuscular mycorrhizae. 
B)  glomerulomycetes that live in root nodules. 
C)  a species of tree that has root nodules. 
D)  actinomycetes that fix nitrogen. 
A)  a type of arbuscular mycorrhizae. 
B)  glomerulomycetes that live in root nodules. 
C)  a species of tree that has root nodules. 
D)  actinomycetes that fix nitrogen.

Question 14

Both pathogenic bacteria and primary symbionts have a tendency to lose genes for catabolic pathways.

Accepted Answer

A) True 
 B)False

Question 15

Hindgut fermenters use a cecum to contain fermentative organisms.

Accepted Answer

A) True 
 B)False

Question 16

A species of insect that lives solely on pine sap was found to contain a bacterial symbiont. Genome sequencing of both the host and the symbiont revealed that the symbiont lacked many genes required for energy production, and the host lacked genes for biosynthesis of several essential amino acids. What is/are the most likely mechanism(s) that caused the loss of these genes?

Accepted Answer

A)  coevolution 
B)  horizontal gene transfer 
C)  increased mutation rate 
D)  horizontal gene transfer and increased mutation rate 
A)  coevolution 
B)  horizontal gene transfer 
C)  increased mutation rate 
D)  horizontal gene transfer and increased mutation rate

Question 17

Which of the following are important adaptations specifically to herbivores?

Accepted Answer

A)  having a large, anoxic chamber where fermentation can occur and having an extended retention time for food 
B)  having a large, oxic chamber where fermentation can occur and having an extended retention time for food 
C)  having a large, anoxic chamber where fermentation can occur and having relatively rapid food passage through the digestive tract 
D)  having a large, oxic chamber where fermentation can occur and having relatively rapid food passage through the digestive tract 
A)  having a large, anoxic chamber where fermentation can occur and having an extended retention time for food 
B)  having a large, oxic chamber where fermentation can occur and having an extended retention time for food 
C)  having a large, anoxic chamber where fermentation can occur and having relatively rapid food passage through the digestive tract 
D)  having a large, oxic chamber where fermentation can occur and having relatively rapid food passage through the digestive tract

Question 18

The structural and trophic foundation of coral reefs is a mutualistic relationship between

Accepted Answer

A)  cyanobacteria and sponges (Porifera). 
B)  chemolithotrophic bacteria and stony corals (Cnidaria). 
C)  dinoflagellates and stony corals (Cnidaria). 
D)  cyanobacteria and stony corals (Cnidaria). 
A)  cyanobacteria and sponges (Porifera). 
B)  chemolithotrophic bacteria and stony corals (Cnidaria). 
C)  dinoflagellates and stony corals (Cnidaria). 
D)  cyanobacteria and stony corals (Cnidaria).

Question 19

During the Jurassic Period, several different mammalian lineages independently evolved an herbivorous lifestyle for obtaining energy. This has resulted in

Accepted Answer

A)  different digestive patterns in herbivorous animals, some that depend on gut microbiota to digest plant material and some that do not. 
B)  different digestive patterns in herbivorous animals that all depend on gut microbiota to digest plant material. 
C)  the evolution of foregut fermentation, as seen in ruminants, as the only digestive pattern that depends on fermentative gut microbiota. 
D)  horizontal gene transfer of genes for glycoside hydrolases and polysaccharide lyases from bacteria to mammals. 
A)  different digestive patterns in herbivorous animals, some that depend on gut microbiota to digest plant material and some that do not. 
B)  different digestive patterns in herbivorous animals that all depend on gut microbiota to digest plant material. 
C)  the evolution of foregut fermentation, as seen in ruminants, as the only digestive pattern that depends on fermentative gut microbiota. 
D)  horizontal gene transfer of genes for glycoside hydrolases and polysaccharide lyases from bacteria to mammals.

Question 20

Describe the mutualistic relationship between chemolithotrophic bacteria and tube worms in hydrothermal vents.

Accepted Answer

The tube worm has a special form of hemo

Exam 23: Microbial Symbioses

The mutualism of Azolla-Anabaena is useful for

How do arbuscular mycorrhizae (AM) help plants obtain more nutrients from the soil?

Which of the following do dinoflagellates most commonly associate with in a mutualistic relationship?

What is one reason that acetogenesis is favored over methanogenesis in the termite gut?

When squids that contain luminescent bacterial symbionts hatch, they do NOT contain a bacterial symbiont. Symbiont transmission in this symbiosis is

Gut symbionts are lost after each molting a termite undergoes.

Both lichens and corals are symbioses involving phototrophic microorganisms. Compare and contrast lichens and corals, including the types of organisms involved, the role of each partner, the specificity of the interaction, and the method of transmission for each symbiosis.

Bacterial cells themselves serve as major sources of protein and vitamins in hindgut fermenting animals such as rabbits and horses.

Which of the following is a common benefit of a microbe-plant symbiosis?

The insect symbiont Wolbachia can be used to suppress disease transmission by mosquitoes because

Secondary symbionts in insects often live

Frankia are

Both pathogenic bacteria and primary symbionts have a tendency to lose genes for catabolic pathways.

Hindgut fermenters use a cecum to contain fermentative organisms.

Which of the following are important adaptations specifically to herbivores?

The structural and trophic foundation of coral reefs is a mutualistic relationship between

During the Jurassic Period, several different mammalian lineages independently evolved an herbivorous lifestyle for obtaining energy. This has resulted in

Describe the mutualistic relationship between chemolithotrophic bacteria and tube worms in hydrothermal vents.

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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