Question 1

Explain the process of bioluminescence in Allivibrio fischeri. How is this an example of a mutualistic relationship?

Accepted Answer

Allivibrio fischeri is bioluminescent at

Question 2

In terms of controlling chemotaxis, the proteins involved control chemotaxis in which way?

Accepted Answer

A)  They control which form of flagellin is expressed. 
B)  They change the direction of the flagella from counterclockwise to clockwise and back. 
C)  They promote longer "tumbles" when a chemoattractant is present. 
D)  They increase the phosphorylation of CheY so that there are more counterclockwise flagella. 
E)  They respond to demethylation of methyl-accepting chemotaxis proteins to bring about longer runs. 
A)  They control which form of flagellin is expressed. 
B)  They change the direction of the flagella from counterclockwise to clockwise and back. 
C)  They promote longer "tumbles" when a chemoattractant is present. 
D)  They increase the phosphorylation of CheY so that there are more counterclockwise flagella. 
E)  They respond to demethylation of methyl-accepting chemotaxis proteins to bring about longer runs.

Question 3

Explain how riboswitches can be compared to activator and repressor proteins. State an example.

Accepted Answer

Just as proteins fold into an active str

Question 4

Explain how small, untranslated RNAs (sRNAs) regulate iron uptake and iron storage.

Accepted Answer

Answers will vary but may include the fo

Question 5

The role of the Hin recombinase is to

Accepted Answer

A)  recombine specific segments of the DNA of Haemophilus influenzae. 
B)  recombine specific segments of flagellin genes in Neisseria gonorrhoeae. 
C)  recombine specific segments of MCP genes in Salmonella enterica. 
D)  recombine specific segments of flagellin genes in Salmonella enterica. 
E)  repair damage in DNA. 
A)  recombine specific segments of the DNA of Haemophilus influenzae. 
B)  recombine specific segments of flagellin genes in Neisseria gonorrhoeae. 
C)  recombine specific segments of MCP genes in Salmonella enterica. 
D)  recombine specific segments of flagellin genes in Salmonella enterica. 
E)  repair damage in DNA.

Question 6

Which form of control is the LEAST reversible and MOST drastic?

Accepted Answer

A)  posttranslational control 
B)  control of transcription 
C)  alterations of DNA sequence 
D)  translational control 
E)  mRNA stability 
A)  posttranslational control 
B)  control of transcription 
C)  alterations of DNA sequence 
D)  translational control 
E)  mRNA stability

Question 7

Some microbes use gene regulation to periodically change their appearance, in a process called

Accepted Answer

A)  sporulation. 
B)  attenuation. 
C)  regulation. 
D)  activation. 
E)  phase variation. 
A)  sporulation. 
B)  attenuation. 
C)  regulation. 
D)  activation. 
E)  phase variation.

Question 8

Which genes always occur in intergenic regions?

Accepted Answer

A)  tRNA 
B)  mRNA 
C)  sRNA 
D)  rRNA 
E)  tsRNA 
A)  tRNA 
B)  mRNA 
C)  sRNA 
D)  rRNA 
E)  tsRNA

Question 9

What does the gene inversion in Salmonella enterica accomplish with respect to its course of infection? Briefly describe how this mechanism works.

Accepted Answer

Changing its flagellar type enables the

Question 10

The stringent response relies on the production of

Accepted Answer

A)  pG. 
B)  ppG. 
C)  pppG. 
D)  pGp. 
E)  ppGpp. 
A)  pG. 
B)  ppG. 
C)  pppG. 
D)  pGp. 
E)  ppGpp.

Question 11

All of the following typically occur in the presence of high glucose and high lactose concentrations EXCEPT

Accepted Answer

A)  enzyme II glucose is unphosphorylated. 
B)  cAMP concentrations are low. 
C)  C-reactive protein levels in the cell are low. 
D)  inhibition of LacY activity. 
E)  lactose is kept out of the cell. 
A)  enzyme II glucose is unphosphorylated. 
B)  cAMP concentrations are low. 
C)  C-reactive protein levels in the cell are low. 
D)  inhibition of LacY activity. 
E)  lactose is kept out of the cell.

Question 12

Explain what happens to motility when a chemoattractant is added to bacterial cells.

Accepted Answer

In the presence of a chemoattractant, th

Question 13

If a cell always needs a gene for housekeeping purposes, it is

Accepted Answer

A)  constitutive. 
B)  inducible. 
C)  repressible. 
D)  derepressible. 
E)  promotable. 
A)  constitutive. 
B)  inducible. 
C)  repressible. 
D)  derepressible. 
E)  promotable.

Question 14

What is diauxic growth and why does it occur?

Accepted Answer

This type of growth occurs when an organ

Question 15

The mechanism behind slipped-strand mispairing is that

Accepted Answer

A)  short repeats allow for slippage of the RNA polymerase during transcription of the affected genes. 
B)  short repeats allow for slippage of DNA polymerase during replication, which leads to an out-of-frame reading sequence. 
C)  an invertible promoter slips into different reading frames. 
D)  the genes coding for lipopolysaccharide in Gram-negative bacteria can be slipped in and out of frame. 
E)  short repeats slip and turn genes off, but they can never be turned back on. 
A)  short repeats allow for slippage of the RNA polymerase during transcription of the affected genes. 
B)  short repeats allow for slippage of DNA polymerase during replication, which leads to an out-of-frame reading sequence. 
C)  an invertible promoter slips into different reading frames. 
D)  the genes coding for lipopolysaccharide in Gram-negative bacteria can be slipped in and out of frame. 
E)  short repeats slip and turn genes off, but they can never be turned back on.

Question 16

The AraC regulator both activates and represses transcription of the genes involved in arabinose catabolism. How is this system more advantageous to a cell than a simpler repressor system like that used on the lac operon?

Accepted Answer

The repressor in the lac operon comes co

Question 17

The araBAD and araC genes are transcribed in the ________ direction with respect to each other.

Accepted Answer

A)  same 
B)  opposite 
C)  forward 
D)  left 
E)  right 
A)  same 
B)  opposite 
C)  forward 
D)  left 
E)  right

Question 18

A quorum-sensing gene system requires the accumulation of a secreted small molecule called a(n)

Accepted Answer

A)  autoinducer. 
B)  activator. 
C)  repressor. 
D)  inducer. 
E)  corepressor. 
A)  autoinducer. 
B)  activator. 
C)  repressor. 
D)  inducer. 
E)  corepressor.

Question 19

Bacterial systems using an AraC/XylS-type regulator include ________ as regulated by ________.

Accepted Answer

A)  a type III secretion system in Pseudomonas; NitR 
B)  a type III secretion system in Pseudomonas; ExsA 
C)  a type III secretion system in Pseudomonas; YbtA 
D)  virulence genes and cholera toxin in Vibrio; TxtR 
E)  virulence genes and cholera toxin in Vibrio; ExsA 
A)  a type III secretion system in Pseudomonas; NitR 
B)  a type III secretion system in Pseudomonas; ExsA 
C)  a type III secretion system in Pseudomonas; YbtA 
D)  virulence genes and cholera toxin in Vibrio; TxtR 
E)  virulence genes and cholera toxin in Vibrio; ExsA

Question 20

In the regulation of chemotaxis, proteins are modified in which of the following ways?

Accepted Answer

A)  phosphorylations 
B)  methylation 
C)  feedback inhibition 
D)  phosphorylation and methylation 
E)  feedback inhibition, phosphorylation, and methylation 
A)  phosphorylations 
B)  methylation 
C)  feedback inhibition 
D)  phosphorylation and methylation 
E)  feedback inhibition, phosphorylation, and methylation

Exam 10: Molecular Regulation

Explain the process of bioluminescence in Allivibrio fischeri. How is this an example of a mutualistic relationship?

In terms of controlling chemotaxis, the proteins involved control chemotaxis in which way?

Explain how riboswitches can be compared to activator and repressor proteins. State an example.

Explain how small, untranslated RNAs (sRNAs) regulate iron uptake and iron storage.

The role of the Hin recombinase is to

Which form of control is the LEAST reversible and MOST drastic?

Some microbes use gene regulation to periodically change their appearance, in a process called

Which genes always occur in intergenic regions?

What does the gene inversion in Salmonella enterica accomplish with respect to its course of infection? Briefly describe how this mechanism works.

The stringent response relies on the production of

All of the following typically occur in the presence of high glucose and high lactose concentrations EXCEPT

Explain what happens to motility when a chemoattractant is added to bacterial cells.

If a cell always needs a gene for housekeeping purposes, it is

What is diauxic growth and why does it occur?

The mechanism behind slipped-strand mispairing is that

The AraC regulator both activates and represses transcription of the genes involved in arabinose catabolism. How is this system more advantageous to a cell than a simpler repressor system like that used on the lac operon?

The araBAD and araC genes are transcribed in the ________ direction with respect to each other.

A quorum-sensing gene system requires the accumulation of a secreted small molecule called a(n)

Bacterial systems using an AraC/XylS-type regulator include ________ as regulated by ________.

In the regulation of chemotaxis, proteins are modified in which of the following ways?

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

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Gene Transfer, Mutations, and Genome Evolution

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Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

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Origins and Evolution

Bacterial Diversity

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Microbes in Global Elemental Cycles

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Bacterial systems using an AraC/XylS-type regulator include as regulated by .