Question 1

When the squid 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 2

Microbial symbionts are horizontally transferred by parental cells directly passing on the symbionts during meiosis.

Accepted Answer

A) True 
 B)False

Question 3

Most nitrogen-fixing bacteria symbiotically associated with plants are called

Accepted Answer

A)  bacteroids. 
B)  mycorrhizae. 
C)  rhizobia. 
D)  symbiodinia. 
A)  bacteroids. 
B)  mycorrhizae. 
C)  rhizobia. 
D)  symbiodinia.

Question 4

Which of the following is a common feature of primary insect symbionts?

Accepted Answer

A)  accelerated mutation rates 
B)  extreme genome reduction 
C)  high A+T / low G+C content 
D)  accelerated mutation rates, extreme genome reduction, and high A+T / low G+C content 
A)  accelerated mutation rates 
B)  extreme genome reduction 
C)  high A+T / low G+C content 
D)  accelerated mutation rates, extreme genome reduction, and high A+T / low G+C content

Question 5

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 tr

Question 6

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

Question 7

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 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 attine ant is entirely dependent on multiple microbial species for its source of food.What microbial species are involved and what is their role in this multi-partner symbiosis?

Accepted Answer

Attine ants purposefully cultivate fungi

Question 10

How do phototrophic microorganisms benefit when associating with corals?

Accepted Answer

A)  Calcium and carbonate ions are released, which help buffer the pH and prevent dramatic pH shifts. 
B)  The coral skeleton is used as a source of bicarbonate for the autotrophic growth of the phototrophs. 
C)  The coral skeleton is an extremely efficient light-gathering structure that greatly enhances light harvesting for photosynthesis. 
D)  The water's temperature in and around the coral skeleton is much warmer. 
A)  Calcium and carbonate ions are released, which help buffer the pH and prevent dramatic pH shifts. 
B)  The coral skeleton is used as a source of bicarbonate for the autotrophic growth of the phototrophs. 
C)  The coral skeleton is an extremely efficient light-gathering structure that greatly enhances light harvesting for photosynthesis. 
D)  The water's temperature in and around the coral skeleton is much warmer.

Question 11

The human oral flora consists of

Accepted Answer

A)  a small group of phylogenetically related aerobic microorganisms. 
B)  diverse aerobic and anaerobic microorganisms. 
C)  monoculture biofilms on tooth surfaces. 
D)  the same phyla that are found in the human gut. 
A)  a small group of phylogenetically related aerobic microorganisms. 
B)  diverse aerobic and anaerobic microorganisms. 
C)  monoculture biofilms on tooth surfaces. 
D)  the same phyla that are found in the human gut.

Question 12

Two-thirds of terrestrial environments support growth of termites.

Accepted Answer

A) True 
 B)False

Question 13

Plant root nodules are

Accepted Answer

A)  formed from gall-rotting bacteria that decompose plant roots. 
B)  harmful to plants, because the bacteria outcompete the plants for nutrients. 
C)  sites where nitrogen fixation occurs. 
D)  structures created by fungi and are found in all agricultural crops. 
A)  formed from gall-rotting bacteria that decompose plant roots. 
B)  harmful to plants, because the bacteria outcompete the plants for nutrients. 
C)  sites where nitrogen fixation occurs. 
D)  structures created by fungi and are found in all agricultural crops.

Question 14

In mycorrhizal mutualisms between plants roots and fungi,

Accepted Answer

A)  the plant supplies carbohydrates to the fungus and the fungus supplies phosphorus and nitrogen to the plant. 
B)  the plant supplies water to the fungus and the fungus supplies essential amino acids to the plant. 
C)  the plant protects the fungus from predation and the fungus supplies carbohydrates to the plant. 
D)  the fungus infects the plant roots, stimulating plant growth through myc factors that act as growth hormones in the plant. 
A)  the plant supplies carbohydrates to the fungus and the fungus supplies phosphorus and nitrogen to the plant. 
B)  the plant supplies water to the fungus and the fungus supplies essential amino acids to the plant. 
C)  the plant protects the fungus from predation and the fungus supplies carbohydrates to the plant. 
D)  the fungus infects the plant roots, stimulating plant growth through myc factors that act as growth hormones in the plant.

Question 15

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 16

A mutant of Rhizobium leguminosarum is able to survive and reproduce in the laboratory outside of plant roots,but can no longer initiate root nodule formation.What type of genes are most likely mutated in this mutant?

Accepted Answer

A)  rhz genes 
B)  myc genes 
C)  nif genes 
D)  nod genes 
A)  rhz genes 
B)  myc genes 
C)  nif genes 
D)  nod genes

Question 17

Genome sequencing of the bacterial symbionts of animals has allowed us to compare the genomic features of several symbionts.The following data were collected on two insect symbionts:
Symbiont A: 0.4 Mb genome,20% G+C content,missing or incomplete peptidoglycan synthesis and nucleotide synthesis pathways.
Symbiont B: 1.8 Mb genome,40% G+C content,peptidoglycan and most nucleotide synthesis pathways complete.
What can you deduce about these two insect symbionts based on their genomes?

Accepted Answer

Symbiont A is likely a vertically transf

Question 18

Riftia tube worms contain unusual hemoglobins that bind(s)

Accepted Answer

A)  H₂S and O₂ in order to transport these chemicals to their bacterial symbionts. 
B)  high concentrations of O₂ produced by their photosynthetic symbionts. 
C)  sulfate to transport this ion away from their bacterial symbionts. 
D)  ammonia that their bacterial symbionts produce. 
A)  H₂S and O₂ in order to transport these chemicals to their bacterial symbionts. 
B)  high concentrations of O₂ produced by their photosynthetic symbionts. 
C)  sulfate to transport this ion away from their bacterial symbionts. 
D)  ammonia that their bacterial symbionts produce.

Question 19

Symbionts such as Aeromonas veronii of leeches and Buchnera symbionts of insects 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 20

Which bacterium contains a large Ti plasmid and causes crown gall disease in plants?

Accepted Answer

A)  Agrobacterium rhizogenes 
B)  Agrobacterium tumefaciens 
C)  Aliivibrio fischeri 
D)  Butyrivibrio fibrisolvens 
A)  Agrobacterium rhizogenes 
B)  Agrobacterium tumefaciens 
C)  Aliivibrio fischeri 
D)  Butyrivibrio fibrisolvens

Exam 22: Microbial Symbioses

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

Microbial symbionts are horizontally transferred by parental cells directly passing on the symbionts during meiosis.

Most nitrogen-fixing bacteria symbiotically associated with plants are called

Which of the following is a common feature of primary insect symbionts?

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.

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

Two main symbionts of termites are ________ and ________.

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

The attine ant is entirely dependent on multiple microbial species for its source of food.What microbial species are involved and what is their role in this multi-partner symbiosis?

How do phototrophic microorganisms benefit when associating with corals?

The human oral flora consists of

Two-thirds of terrestrial environments support growth of termites.

Plant root nodules are

In mycorrhizal mutualisms between plants roots and fungi,

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

A mutant of Rhizobium leguminosarum is able to survive and reproduce in the laboratory outside of plant roots,but can no longer initiate root nodule formation.What type of genes are most likely mutated in this mutant?

Riftia tube worms contain unusual hemoglobins that bind(s)

Symbionts such as Aeromonas veronii of leeches and Buchnera symbionts of insects are transmitted ________ to ensure the safe transfer of the symbiont to the next host generation.

Which bacterium contains a large Ti plasmid and causes crown gall disease in plants?

Microorganisms and Microbiology

Microbial Cell Structure and Function

Microbial Metabolism

Molecular Biology

Microbial Growth and Control

Microbial Genomics

Metabolic Regulation

Viruses and Virology

Viral Genomes and Diversity

Genetics of Bacteria and Archaea

Genetic Engineering and Biotechnology

Microbial Evolution and Systematics

Metabolic Diversity of Microorganisms

Functional Diversity of Bacteria

Diversity of Bacteria

Diversity of Archaea

Diversity of Eukaryotic Microorganisms

Methods in Microbial Ecology

Microbial Ecosystems

Nutrient Cycles

Microbiology of the Built Environment

Microbial Interactions With Humans

Immunity and Host Defense

Immune Mechanisms

Molecular Immunology

Diagnostic Microbiology

Epidemiology

Person-To-Person Bacterial and Viral Diseases

Vectorborne and Soilborne Bacterial and Viral Diseases

Water and Food As Vehicles of Bacterial Diseases

Eukaryotic Pathogens: Fungal and Parasitic Diseases

Filters

Two main symbionts of termites are and .