Question 1

Describe what happens to the lac operon in the presence of both lactose and glucose.

Accepted Answer

In the presence of both lactose and gluc

Question 2

Transcriptional attenuation is a common regulatory strategy used to control many operons that code for

Accepted Answer

A)  amino acid degradation. 
B)  amino acid biosynthesis. 
C)  carbohydrate degradation. 
D)  carbohydrate biosynthesis. 
E)  lipid degradation. 
A)  amino acid degradation. 
B)  amino acid biosynthesis. 
C)  carbohydrate degradation. 
D)  carbohydrate biosynthesis. 
E)  lipid degradation.

Question 3

How is sigma H degradation controlled by temperature, and why is this important to the cell?

Accepted Answer

At lower temperatures, chaperones bring

Question 4

Autoinducers regulate gene expression by

Accepted Answer

A)  accumulating inside the cell until enough is present to bind repressor proteins and stop transcription. 
B)  accumulating inside the cell until enough is present to bind activator proteins and initiate transcription. 
C)  interacting with small RNAs to either inhibit or enhance transcription. 
D)  diffusing out of the cell and when a critical cell density is reached, moving back in and binding to a regulatory protein to initiate transcription. 
E)  being synthesized after glucose is used up, thereby bypassing catabolite repression. 
A)  accumulating inside the cell until enough is present to bind repressor proteins and stop transcription. 
B)  accumulating inside the cell until enough is present to bind activator proteins and initiate transcription. 
C)  interacting with small RNAs to either inhibit or enhance transcription. 
D)  diffusing out of the cell and when a critical cell density is reached, moving back in and binding to a regulatory protein to initiate transcription. 
E)  being synthesized after glucose is used up, thereby bypassing catabolite repression.

Question 5

Which of the following is the favored carbon source of Escherichia coli?

Accepted Answer

A)  lactose 
B)  galactose 
C)  sucrose 
D)  glucose 
E)  fructose 
A)  lactose 
B)  galactose 
C)  sucrose 
D)  glucose 
E)  fructose

Question 6

A bacterial growth curve is presented below. The curve represents ________ growth, which is caused by the ________.

Accepted Answer

A)  binary; addition of more growth media after the fulture reaches stationary phase 
B)  diauxic; addition of more growth media after the fulture reaches stationary phase 
C)  binary; addition of a needed vitamin after it runs out 
D)  diauxic; addition of a needed vitamin after it runs out 
E)  diauxic; growth on two carbon sources resulting in a lag after the preferred substrate is depleted; new genes are then induced and growth resumes 
A)  binary; addition of more growth media after the fulture reaches stationary phase 
B)  diauxic; addition of more growth media after the fulture reaches stationary phase 
C)  binary; addition of a needed vitamin after it runs out 
D)  diauxic; addition of a needed vitamin after it runs out 
E)  diauxic; growth on two carbon sources resulting in a lag after the preferred substrate is depleted; new genes are then induced and growth resumes

Question 7

With respect to quorum sensing, all of the following are true EXCEPT that it

Accepted Answer

A)  can be involved in cross-talk between species, including eukaryotes. 
B)  can be involved in some pathogenesis and biofilm formation. 
C)  has only one autoinduction system per species. 
D)  is carried out with an autoinducer such as homoserine lactone. 
E)  plays a role in some antibiotic production. 
A)  can be involved in cross-talk between species, including eukaryotes. 
B)  can be involved in some pathogenesis and biofilm formation. 
C)  has only one autoinduction system per species. 
D)  is carried out with an autoinducer such as homoserine lactone. 
E)  plays a role in some antibiotic production.

Question 8

If the newly synthesized DNA strand slips back relative to the template strand, one copy of the repeated unit is ________ the growing strand.

Accepted Answer

A)  inserted in 
B)  deleted from 
C)  folded over 
D)  folded under 
E)  bound to 
A)  inserted in 
B)  deleted from 
C)  folded over 
D)  folded under 
E)  bound to

Question 9

How does the AraC regulatory protein turn on transcription in the presence of arabinose?

Accepted Answer

A)  With the addition of arabinose, AraC no longer dimerizes and will form a large loop by binding to araO and aria, and thus can interact with RNA polymerase to permit transcription. 
B)  The dimer will form a large loop by binding to araO and aria, and thus can interact with RNA polymerase to permit transcription. 
C)  With the addition, AraC no longer dimerizes and thus can interact with RNA polymerase to permit transcription. 
D)  It becomes less flexible, so that a monomer can bind to araI1 and araI2 and interact with RNA polymerase to permit transcription. 
E)  It becomes more flexible, so that the dimer can bind to araI1 and araI2 and interact with RNA polymerase to permit transcription. 
A)  With the addition of arabinose, AraC no longer dimerizes and will form a large loop by binding to araO and aria, and thus can interact with RNA polymerase to permit transcription. 
B)  The dimer will form a large loop by binding to araO and aria, and thus can interact with RNA polymerase to permit transcription. 
C)  With the addition, AraC no longer dimerizes and thus can interact with RNA polymerase to permit transcription. 
D)  It becomes less flexible, so that a monomer can bind to araI1 and araI2 and interact with RNA polymerase to permit transcription. 
E)  It becomes more flexible, so that the dimer can bind to araI1 and araI2 and interact with RNA polymerase to permit transcription.

Question 10

In a two-component signal transduction system, a ________ is transferred from a sensor kinase to a ________ in response to an environmental signal.

Accepted Answer

A)  phosphate; sensor domain 
B)  phosphate; sensor phosphatase 
C)  phosphate; response regulator 
D)  magnesium; sensor domain 
E)  magnesium; response regulator 
A)  phosphate; sensor domain 
B)  phosphate; sensor phosphatase 
C)  phosphate; response regulator 
D)  magnesium; sensor domain 
E)  magnesium; response regulator

Question 11

Which of the following is a technique used in studying the proteome of an organism?

Accepted Answer

A)  knowing the DNA sequence to predict the amino acid sequence 
B)  predicting the protein sequence by using the mRNA sequence 
C)  two-dimensional protein gels followed by mass spec of the proteins 
D)  obtaining cDNA and then probing a DNA microarray 
E)  digesting a cell extract with trypsin 
A)  knowing the DNA sequence to predict the amino acid sequence 
B)  predicting the protein sequence by using the mRNA sequence 
C)  two-dimensional protein gels followed by mass spec of the proteins 
D)  obtaining cDNA and then probing a DNA microarray 
E)  digesting a cell extract with trypsin

Question 12

The stringent response downregulates rRNA synthesis. Does it similarly downregulate ribosomal protein synthesis?

Accepted Answer

Ribosomal protein synthesis will also sl

Question 13

During the process of endospore formation, different sigma factors are active in the mother cell and forespore. How is this possible, and why is it important?

Accepted Answer

When the septum is formed and the foresp

Question 14

The value of studying a transcriptome rather than a genome is that

Accepted Answer

A)  RNA is much easier to work with than DNA. 
B)  using bacterial RNA eliminates the introns they all have. 
C)  one can get a snapshot of what genes are expressed under some conditions but not others. 
D)  a transcriptome is more related to the protein. 
E)  deep sequencing can only be performed on RNA. 
A)  RNA is much easier to work with than DNA. 
B)  using bacterial RNA eliminates the introns they all have. 
C)  one can get a snapshot of what genes are expressed under some conditions but not others. 
D)  a transcriptome is more related to the protein. 
E)  deep sequencing can only be performed on RNA.

Question 15

The stringent response involves all EXCEPT

Accepted Answer

A)  downregulation of rRNA synthesis. 
B)  downregulation of tRNA synthesis. 
C)  ATP. 
D)  GTP. 
E)  a lack of change in gene expression. 
A)  downregulation of rRNA synthesis. 
B)  downregulation of tRNA synthesis. 
C)  ATP. 
D)  GTP. 
E)  a lack of change in gene expression.

Question 16

Quorum sensing plays a role in interspecies communications. Describe the relationship between green seaweed Enteromorpha and Vibrio anguillarum bacterial cells in biofilms, and explain how Escherichia coli was used to understand this interaction.

Accepted Answer

Enteromorpha makes motile zoospores that

Question 17

In some, but not all, instances, ________ molecules bind RNA transcripts and help or hinder degradation.

Accepted Answer

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

Question 18

All the cell's expressed RNAs are collectively referred to as the cell's

Accepted Answer

A)  genome. 
B)  transcriptome. 
C)  proteome. 
D)  holoenzyme. 
E)  ORF. 
A)  genome. 
B)  transcriptome. 
C)  proteome. 
D)  holoenzyme. 
E)  ORF.

Question 19

Explain the process of attenuation in regulating transcription of the tryptophan operon.

Accepted Answer

Attenuation is a process of transcriptio

Question 20

A transmembrane sensor kinase protein senses an environmental condition outside ________ bacteria or in the periplasm of a(n) ________ bacteria.

Accepted Answer

A)  Gram-positive; Gram-negative 
B)  Gram-negative; Gram-positive 
C)  prokaryotic; eukaryotic 
D)  prokaryotic; archaean 
E)  Gram-positive; acid-fast 
A)  Gram-positive; Gram-negative 
B)  Gram-negative; Gram-positive 
C)  prokaryotic; eukaryotic 
D)  prokaryotic; archaean 
E)  Gram-positive; acid-fast

Exam 10: Molecular Regulation

Describe what happens to the lac operon in the presence of both lactose and glucose.

Transcriptional attenuation is a common regulatory strategy used to control many operons that code for

How is sigma H degradation controlled by temperature, and why is this important to the cell?

Autoinducers regulate gene expression by

Which of the following is the favored carbon source of Escherichia coli?

A bacterial growth curve is presented below. The curve represents ________ growth, which is caused by the ________.

With respect to quorum sensing, all of the following are true EXCEPT that it

If the newly synthesized DNA strand slips back relative to the template strand, one copy of the repeated unit is ________ the growing strand.

How does the AraC regulatory protein turn on transcription in the presence of arabinose?

In a two-component signal transduction system, a ________ is transferred from a sensor kinase to a ________ in response to an environmental signal.

Which of the following is a technique used in studying the proteome of an organism?

The stringent response downregulates rRNA synthesis. Does it similarly downregulate ribosomal protein synthesis?

During the process of endospore formation, different sigma factors are active in the mother cell and forespore. How is this possible, and why is it important?

The value of studying a transcriptome rather than a genome is that

The stringent response involves all EXCEPT

Quorum sensing plays a role in interspecies communications. Describe the relationship between green seaweed Enteromorpha and Vibrio anguillarum bacterial cells in biofilms, and explain how Escherichia coli was used to understand this interaction.

In some, but not all, instances, ________ molecules bind RNA transcripts and help or hinder degradation.

All the cell's expressed RNAs are collectively referred to as the cell's

Explain the process of attenuation in regulating transcription of the tryptophan operon.

A transmembrane sensor kinase protein senses an environmental condition outside ________ bacteria or in the periplasm of a(n) ________ bacteria.

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

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

Microbial Ecology

Microbes in Global Elemental Cycles

Human Microbiota and Innate Immunity

The Adaptive Immune Response

Microbial Pathogenesis

Microbial Diseases

Antimicrobial Therapy

Clinical Microbiology and Epidemiology

Filters

A bacterial growth curve is presented below. The curve represents growth, which is caused by the .

In a two-component signal transduction system, a is transferred from a sensor kinase to a in response to an environmental signal.

A transmembrane sensor kinase protein senses an environmental condition outside bacteria or in the periplasm of a(n) bacteria.