Question 1

A feature common to all control mechanisms is

Accepted Answer

A)  quorum sensing. 
B)  phosphorylation cascades. 
C)  the ability to sense that something inside or around the cell has changed. 
D)  housekeeping enzymes. 
E)  increased or decreased gene expression. 
A)  quorum sensing. 
B)  phosphorylation cascades. 
C)  the ability to sense that something inside or around the cell has changed. 
D)  housekeeping enzymes. 
E)  increased or decreased gene expression. C

Question 2

Which of the following is NOT true of sRNA genes?

Accepted Answer

A)  They have a ribosomal-binding site. 
B)  They occur between genes. 
C)  They share homology between related species. 
D)  They can act as antisense RNAs. 
E)  They play a role in regulating genes involved in oxidative stress, acid resistance, and quorum sensing. 
A)  They have a ribosomal-binding site. 
B)  They occur between genes. 
C)  They share homology between related species. 
D)  They can act as antisense RNAs. 
E)  They play a role in regulating genes involved in oxidative stress, acid resistance, and quorum sensing. A

Question 3

Which of the following statements about riboswitches is true?

Accepted Answer

A)  They are found mainly at the 3' end of a mRNA. 
B)  They are capable of binding to a ligand and activating transcription but do not repress transcription. 
C)  They can control transcription but no translation. 
D)  Ligands that can bind range from vitamins, amino acids, magnesium, and fluoride. 
E)  They have no secondary structures involved in their control. 
A)  They are found mainly at the 3' end of a mRNA. 
B)  They are capable of binding to a ligand and activating transcription but do not repress transcription. 
C)  They can control transcription but no translation. 
D)  Ligands that can bind range from vitamins, amino acids, magnesium, and fluoride. 
E)  They have no secondary structures involved in their control. D

Question 4

Glucose transport into the cell brings about a phenomenon known as inducer exclusion.
Describe how this functions with respect to the lac operon.

Accepted Answer

In the presence of glucose, the PTS syst

Question 5

How is repression of biosynthetic pathways different than repression of a catabolic pathway? Why does repression of these two types of pathways work differently?

Accepted Answer

Repressors that control catabolic pathwa

Question 6

Finding an inverted repeated sequence within 100-200 bases of a promoter suggests the presence of a ________ binding site.

Accepted Answer

A)  DNA 
B)  transcriptional regulator 
C)  RNA 
D)  ribosome 
E)  corepressor 
A)  DNA 
B)  transcriptional regulator 
C)  RNA 
D)  ribosome 
E)  corepressor

Question 7

When both glucose and lactose are added to the growth medium, Escherichia coli will have a growth curve that

Accepted Answer

A)  does not change. 
B)  grows slowly and then, halfway through, grows faster. 
C)  grows, levels off, and then grows again. 
D)  grows more slowly than with glucose alone. 
E)  grows more quickly than with glucose alone. 
A)  does not change. 
B)  grows slowly and then, halfway through, grows faster. 
C)  grows, levels off, and then grows again. 
D)  grows more slowly than with glucose alone. 
E)  grows more quickly than with glucose alone.

Question 8

The role of a leader sequence is to

Accepted Answer

A)  directly control transcription. 
B)  determine whether transcription can proceed through the genes in the operon. 
C)  determine whether RNA polymerase can bind. 
D)  terminate transcription. 
E)  direct the looping of the DNA that prevents transcription initiation. 
A)  directly control transcription. 
B)  determine whether transcription can proceed through the genes in the operon. 
C)  determine whether RNA polymerase can bind. 
D)  terminate transcription. 
E)  direct the looping of the DNA that prevents transcription initiation.

Question 9

Explain how a repressor protein works with respect to a biosynthetic operon.

Accepted Answer

When the end product of the biosynthetic

Question 10

The best description of the initial step in the regulatory process shown below is

Accepted Answer

A)  an sRNA is produced that can then be used to turn on genes. 
B)  an sRNA is produced that can then be used to turn off genes. 
C)  a sigma factor mRNA is transcribed and forms secondary structures at lower temperatures. When heated, the structures melt and the mRNA for the heat shock sigma factor, rpoH, can be translated. 
D)  The hairpins contain codons for a needed amino acid. When amino acid is lacking, the ribosome stalls and prevents its formation, thus allowing translation. 
E)  The hairpins contain codons for needed amino acids. When amino acid is present, the ribosome stalls and prevents the formation of hairpins, thus allowing translation. 
A)  an sRNA is produced that can then be used to turn on genes. 
B)  an sRNA is produced that can then be used to turn off genes. 
C)  a sigma factor mRNA is transcribed and forms secondary structures at lower temperatures. When heated, the structures melt and the mRNA for the heat shock sigma factor, rpoH, can be translated. 
D)  The hairpins contain codons for a needed amino acid. When amino acid is lacking, the ribosome stalls and prevents its formation, thus allowing translation. 
E)  The hairpins contain codons for needed amino acids. When amino acid is present, the ribosome stalls and prevents the formation of hairpins, thus allowing translation.

Question 11

Which of the following is a second messenger that helps to regulate biofilm production?

Accepted Answer

A)  ppGpp 
B)  ATP 
C)  cAMP 
D)  cGMP 
E)  cdiGMP 
A)  ppGpp 
B)  ATP 
C)  cAMP 
D)  cGMP 
E)  cdiGMP

Question 12

What type of RNAs bind to complementary sequences of target transcripts and stimulate or prevent translation?

Accepted Answer

A)  ribosomal 
B)  transfer 
C)  messenger 
D)  antisense 
E)  small 
A)  ribosomal 
B)  transfer 
C)  messenger 
D)  antisense 
E)  small

Question 13

Integrated circuits are involved in all of the following EXCEPT

Accepted Answer

A)  controlling chemotactic activities of a cell. 
B)  coupling the genetic and biochemical control of a metabolic pathway. 
C)  timing the events of a developmental cycle. 
D)  having an influence on nitrogen metabolism. 
E)  specifically inverting the flagellin genes. 
A)  controlling chemotactic activities of a cell. 
B)  coupling the genetic and biochemical control of a metabolic pathway. 
C)  timing the events of a developmental cycle. 
D)  having an influence on nitrogen metabolism. 
E)  specifically inverting the flagellin genes.

Question 14

One benefit of operons in bacteria is that they

Accepted Answer

A)  allow for alterations in DNA sequence by flipping promoters around. 
B)  allow for coordinated gene expression of related genes on one mRNA controlled by one promoter. 
C)  do not need ligands and regulatory proteins as single genes would. 
D)  do not need any modification of the proteins after they are expressed. 
E)  allow for the bacteria to utilize a wide variety of carbon sources. 
A)  allow for alterations in DNA sequence by flipping promoters around. 
B)  allow for coordinated gene expression of related genes on one mRNA controlled by one promoter. 
C)  do not need ligands and regulatory proteins as single genes would. 
D)  do not need any modification of the proteins after they are expressed. 
E)  allow for the bacteria to utilize a wide variety of carbon sources.

Question 15

Which of the following statements is true concerning the use of cyclic di-GMP as a second messenger?

Accepted Answer

A)  It activates the expression of flagellin genes and thus enhances motility. 
B)  It is found in all microbes: bacteria, archaea, and eukaryotic microbes. 
C)  The action of diguanylate cyclase produces it. 
D)  It decreases in level as biofilm is produced. 
E)  Phosphodiesterase can convert GMP to cyclic di-GMP. 
A)  It activates the expression of flagellin genes and thus enhances motility. 
B)  It is found in all microbes: bacteria, archaea, and eukaryotic microbes. 
C)  The action of diguanylate cyclase produces it. 
D)  It decreases in level as biofilm is produced. 
E)  Phosphodiesterase can convert GMP to cyclic di-GMP.

Question 16

The figure below shows a regulatory being produced on the left. Based on the information in the figure, this protein must function in which of the following ways?

Accepted Answer

A)  When glucose binds to it, the protein binds to the regulatory sequence and prevents transcription of the target gene. 
B)  This protein must influence a hairpin sequence and thus fine tunes the operon. 
C)  In the presence of the end product of the operon, this protein will bind to the regulatory region and acts as an activator. 
D)  When a ligand is or is not bound, this protein may act as either an activator or repressor. 
E)  This protein would not have an effect on transcription of the target gene. 
A)  When glucose binds to it, the protein binds to the regulatory sequence and prevents transcription of the target gene. 
B)  This protein must influence a hairpin sequence and thus fine tunes the operon. 
C)  In the presence of the end product of the operon, this protein will bind to the regulatory region and acts as an activator. 
D)  When a ligand is or is not bound, this protein may act as either an activator or repressor. 
E)  This protein would not have an effect on transcription of the target gene.

Question 17

The regulatory activity of sRNA

Accepted Answer

A)  codes for a sigma factor. 
B)  prevents CRP interaction with RNA polymerase, thereby blocking its access to the promoter. 
C)  synthesizes ppGpp. 
D)  targets mRNAs for degradation. 
E)  creates an attenuator stem loop. 
A)  codes for a sigma factor. 
B)  prevents CRP interaction with RNA polymerase, thereby blocking its access to the promoter. 
C)  synthesizes ppGpp. 
D)  targets mRNAs for degradation. 
E)  creates an attenuator stem loop.

Question 18

Which of the following describes the process of obtaining RNA sequence information?

Accepted Answer

A)  Proteins are isolated and mass spec is used. Once the proteins are known, the RNA that coded for them can be determined. 
B)  RNA from a particular growth condition is isolated and converted to cDNA; DNA adapters are added, allowing high-throughput sequencing to be carried out. The genome position of the sequence obtained is then determined using computer software. 
C)  A DNA microarray is used to find the RNA sequences expressed at that time. 
D)  One examines the tRNA and rRNA in a given culture in order to study various physiological conditions. 
E)  One determines the RNA sequence of every gene in the genome and then determines if it is present in a given culture. 
A)  Proteins are isolated and mass spec is used. Once the proteins are known, the RNA that coded for them can be determined. 
B)  RNA from a particular growth condition is isolated and converted to cDNA; DNA adapters are added, allowing high-throughput sequencing to be carried out. The genome position of the sequence obtained is then determined using computer software. 
C)  A DNA microarray is used to find the RNA sequences expressed at that time. 
D)  One examines the tRNA and rRNA in a given culture in order to study various physiological conditions. 
E)  One determines the RNA sequence of every gene in the genome and then determines if it is present in a given culture.

Question 19

________ prevent transcription, whereas ________ stimulate transcription.

Accepted Answer

A)  Activators; repressors 
B)  Inducers; corepressors 
C)  Corepressors; inducers 
D)  Regulators; repressors 
E)  Repressors; activators 
A)  Activators; repressors 
B)  Inducers; corepressors 
C)  Corepressors; inducers 
D)  Regulators; repressors 
E)  Repressors; activators

Question 20

Binding of tryptophan to the ________ makes a holorepressor.

Accepted Answer

A)  aporepressor 
B)  corepressor 
C)  repressor 
D)  inducer 
E)  activator 
A)  aporepressor 
B)  corepressor 
C)  repressor 
D)  inducer 
E)  activator

Exam 10: Molecular Regulation

A feature common to all control mechanisms is

Which of the following is NOT true of sRNA genes?

Which of the following statements about riboswitches is true?

Glucose transport into the cell brings about a phenomenon known as inducer exclusion. Describe how this functions with respect to the lac operon.

How is repression of biosynthetic pathways different than repression of a catabolic pathway? Why does repression of these two types of pathways work differently?

Finding an inverted repeated sequence within 100-200 bases of a promoter suggests the presence of a ________ binding site.

When both glucose and lactose are added to the growth medium, Escherichia coli will have a growth curve that

The role of a leader sequence is to

Explain how a repressor protein works with respect to a biosynthetic operon.

The best description of the initial step in the regulatory process shown below is

Which of the following is a second messenger that helps to regulate biofilm production?

What type of RNAs bind to complementary sequences of target transcripts and stimulate or prevent translation?

Integrated circuits are involved in all of the following EXCEPT

One benefit of operons in bacteria is that they

Which of the following statements is true concerning the use of cyclic di-GMP as a second messenger?

The figure below shows a regulatory being produced on the left. Based on the information in the figure, this protein must function in which of the following ways?

The regulatory activity of sRNA

Which of the following describes the process of obtaining RNA sequence information?

________ prevent transcription, whereas ________ stimulate transcription.

Binding of tryptophan to the ________ makes a holorepressor.

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

prevent transcription, whereas stimulate transcription.