Question 1

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 2

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 3

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 4

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 5

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 6

Explain a way that organisms sense and respond to their environment.

Accepted Answer

Answers vary but could include the follo

Question 7

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 8

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 9

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

Question 10

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 11

Which molecule is used for hybridization to DNA bound on a DNA microarray?

Accepted Answer

A)  DNA 
B)  RNA 
C)  mRNA 
D)  cDNA 
E)  qDNA 
A)  DNA 
B)  RNA 
C)  mRNA 
D)  cDNA 
E)  qDNA

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

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

Exam 10: Molecular Regulation

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

Autoinducers regulate gene expression by

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

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

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

Explain a way that organisms sense and respond to their environment.

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

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?

Binding of tryptophan to the ________ makes a holorepressor.

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?

Which molecule is used for hybridization to DNA bound on a DNA microarray?

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

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

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

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