Question 1

Which of the following viral groups has been successfully utilized as vector in gene therapy?

Accepted Answer

A)  rhabdoviruses 
B)  parvoviruses 
C)  lentiviruses 
D)  orthomyxoviruses 
E)  bacteriophages 
A)  rhabdoviruses 
B)  parvoviruses 
C)  lentiviruses 
D)  orthomyxoviruses 
E)  bacteriophages C

Question 2

What are retroelements and why do they exist within the human genome?

Accepted Answer

Retroelements are remnants of decaying retroviral genomes. They integrated into the human genome and then lost the ability to produce progeny and so became trapped within a cell. Endogenous retroviruses contain all of the genomic elements of a retrovirus but never generate virions because they have lost this ability due to mutations. Retrotransposons have only some of the retroviral elements but maintain a reverse transcriptase and so can copy themselves to other locations.

Question 3

Use the figure below to describe the events leading to the fusion between influenza virus A and host membranes. What structures are indicated by the numbers?

Accepted Answer

Influenza virions enter the cell by endocytosis after binding sialic-acid-containing receptors (4). A host protease cleaves the carboxy terminal domain of hemagglutinin (2), leading to the formation of amino terminal hemagglutinin fusion peptides. The virus-harboring endosome fuses with a lysosome and its interior acidifies (5), contributing to conformational changes of the fusion peptides on the viral envelope (1); namely, the N-terminal regions of the fusion peptides protrude toward the vesicle membrane. This brings closer the envelope to the host's cell membranes (3), leading to membrane fusion (lower panel) and subsequent release of the virion contents into the cytoplasm.

Question 4

Approximately 60%-80% of Americans acquire herpes simplex, usually HSV-1, in epithelial lesions commonly known as

Accepted Answer

A)  chancres. 
B)  pox. 
C)  cold sores. 
D)  shingles. 
E)  hives. 
A)  chancres. 
B)  pox. 
C)  cold sores. 
D)  shingles. 
E)  hives.

Question 5

Proteolysis of the influenza ________ produces a fusion peptide, which initially binds to a ________ glycoprotein on the host's cell membrane that serves as a receptor.

Accepted Answer

A)  hemagglutinin; syalic acid 
B)  neuraminidase; N-acetylglucosamine 
C)  matrix; fucose 
D)  nuclear-packaging protein; mannose 
E)  nucleocapsid protein; glucosamine 
A)  hemagglutinin; syalic acid 
B)  neuraminidase; N-acetylglucosamine 
C)  matrix; fucose 
D)  nuclear-packaging protein; mannose 
E)  nucleocapsid protein; glucosamine

Question 6

The genome of the influenza virus is best described as

Accepted Answer

A)  (-) strand segmented RNA. 
B)  (+) strand segmented RNA. 
C)  (-) strand single-piece RNA. 
D)  (+) strand single-piece RNA. 
E)  double-stranded RNA. 
A)  (-) strand segmented RNA. 
B)  (+) strand segmented RNA. 
C)  (-) strand single-piece RNA. 
D)  (+) strand single-piece RNA. 
E)  double-stranded RNA.

Question 7

Why is it advantageous to use lentivectors to treat diseases that affect nondividing cells?

Accepted Answer

Accessory protein Vpr allows lentiviruse

Question 8

How many genomes does an HIV particle have and what is their biochemical nature?

Accepted Answer

A)  two RNA molecules 
B)  eight RNA molecules 
C)  a DNA/RNA hybrid 
D)  a single RNA molecule 
E)  a DNA molecule and a noncomplementary RNA molecule 
A)  two RNA molecules 
B)  eight RNA molecules 
C)  a DNA/RNA hybrid 
D)  a single RNA molecule 
E)  a DNA molecule and a noncomplementary RNA molecule

Question 9

Describe the several features of lentivectors. What are their molecular sources?

Accepted Answer

A lentivirus such as HIV is engineered t

Question 10

Retroelements are remains of retroviral genomes in various states of decay. Which of the following are NOT retroelements?

Accepted Answer

A)  Alu sequences 
B)  HERVs 
C)  LINE 
D)  Gene transfer vectors 
E)  SINE 
A)  Alu sequences 
B)  HERVs 
C)  LINE 
D)  Gene transfer vectors 
E)  SINE

Question 11

Cyclophilin A is a host protein that

Accepted Answer

A)  acts as a coreceptor for HIV. 
B)  facilitates HIV entry into the nucleus. 
C)  is incorporated in the HIV envelope. 
D)  inhibits HIV replication. 
E)  cuts the polyprotein into subunits. 
A)  acts as a coreceptor for HIV. 
B)  facilitates HIV entry into the nucleus. 
C)  is incorporated in the HIV envelope. 
D)  inhibits HIV replication. 
E)  cuts the polyprotein into subunits.

Question 12

How does the herpes simplex virus genome reach the interior of an infected cell?

Accepted Answer

A)  The core particle partly uncoats after entering the cytoplasm. 
B)  The intact viral capsid travels down a scaffold of microtubules to a nuclear pore. 
C)  The viral particle enters the cell by endocytosis and releases virion contents into the cytoplasm. 
D)  The capsid remains outside the cell; the nucleic acid is threaded through a receptor in the membrane. 
E)  DNA is forced into the capsid. 
A)  The core particle partly uncoats after entering the cytoplasm. 
B)  The intact viral capsid travels down a scaffold of microtubules to a nuclear pore. 
C)  The viral particle enters the cell by endocytosis and releases virion contents into the cytoplasm. 
D)  The capsid remains outside the cell; the nucleic acid is threaded through a receptor in the membrane. 
E)  DNA is forced into the capsid.

Question 13

The figure below is a transmission electron microscopy image of an influenza A virion. Hemagglutinin (HA) is one of the spike proteins. Which is the other spike protein on the envelope of influenza A?

Accepted Answer

A)  nucleocapsid protein 
B)  ion channel 
C)  matrix protein 
D)  nuclear export protein 
E)  neuraminidase 
A)  nucleocapsid protein 
B)  ion channel 
C)  matrix protein 
D)  nuclear export protein 
E)  neuraminidase

Question 14

Which type of virus has been successfully used in the treatment of diseases such as B-cell leukemia and adrenoleukodystrophy?

Accepted Answer

A)  lentivirus 
B)  adenovirus 
C)  poliovirus 
D)  influenza virus 
E)  T4 
A)  lentivirus 
B)  adenovirus 
C)  poliovirus 
D)  influenza virus 
E)  T4

Question 15

What vertebrate groups harbor influenza viruses capable of mutating into strains infective to humans?

Accepted Answer

A)  cattle and horses 
B)  swine and cattle 
C)  birds and swine 
D)  mice and rats 
E)  canines and felines 
A)  cattle and horses 
B)  swine and cattle 
C)  birds and swine 
D)  mice and rats 
E)  canines and felines

Question 16

Influenza shows cyclic appearance of extremely virulent strains that may cause widespread infection with high mortality, such as that of 1918, which infected 20% of the world's population and killed more people than World War I. What is this type of infection called?

Accepted Answer

A)  mutagenic 
B)  endemic 
C)  epidemic 
D)  pandemic 
E)  transgenic 
A)  mutagenic 
B)  endemic 
C)  epidemic 
D)  pandemic 
E)  transgenic

Question 17

Which of the following statements is FALSE regarding phage lambda as a temperate phage?

Accepted Answer

A)  The genome of phage lambda integrates into the genome of the host cell and becomes a prophage. 
B)  The phage DNA replicates as an integrated prophage but does not produce phage particles. 
C)  Lambda phage immediately kills its host after infection. 
D)  The presence of the lambda prophage confers resistant to new infections by lambda. 
E)  Incorporation of lambda phage DNA into the bacterial genome is called lysogeny. 
A)  The genome of phage lambda integrates into the genome of the host cell and becomes a prophage. 
B)  The phage DNA replicates as an integrated prophage but does not produce phage particles. 
C)  Lambda phage immediately kills its host after infection. 
D)  The presence of the lambda prophage confers resistant to new infections by lambda. 
E)  Incorporation of lambda phage DNA into the bacterial genome is called lysogeny.

Question 18

How is lambda phage being used to fight the problem of antibiotic resistance in bacteria?

Accepted Answer

A lambda phage that can specifically eli

Question 19

The lymphocyte protein chemokine receptor 5 (CCR5) is involved in HIV. Functionally, CCR5 is a(n)

Accepted Answer

A)  antagonist. 
B)  coreceptor. 
C)  cofactor. 
D)  inhibitor. 
E)  regulator. 
A)  antagonist. 
B)  coreceptor. 
C)  cofactor. 
D)  inhibitor. 
E)  regulator.

Question 20

The pol open reading frame of HIV encodes

Accepted Answer

A)  reverse transcriptase. 
B)  integrase. 
C)  protease. 
D)  gyrase. 
E)  ligase. 
A)  reverse transcriptase. 
B)  integrase. 
C)  protease. 
D)  gyrase. 
E)  ligase.

Exam 11: Viral Molecular Biology

Which of the following viral groups has been successfully utilized as vector in gene therapy?

What are retroelements and why do they exist within the human genome?

Use the figure below to describe the events leading to the fusion between influenza virus A and host membranes. What structures are indicated by the numbers?

Approximately 60%-80% of Americans acquire herpes simplex, usually HSV-1, in epithelial lesions commonly known as

Proteolysis of the influenza ________ produces a fusion peptide, which initially binds to a ________ glycoprotein on the host's cell membrane that serves as a receptor.

The genome of the influenza virus is best described as

Why is it advantageous to use lentivectors to treat diseases that affect nondividing cells?

How many genomes does an HIV particle have and what is their biochemical nature?

Describe the several features of lentivectors. What are their molecular sources?

Retroelements are remains of retroviral genomes in various states of decay. Which of the following are NOT retroelements?

Cyclophilin A is a host protein that

How does the herpes simplex virus genome reach the interior of an infected cell?

The figure below is a transmission electron microscopy image of an influenza A virion. Hemagglutinin (HA) is one of the spike proteins. Which is the other spike protein on the envelope of influenza A?

Which type of virus has been successfully used in the treatment of diseases such as B-cell leukemia and adrenoleukodystrophy?

What vertebrate groups harbor influenza viruses capable of mutating into strains infective to humans?

Influenza shows cyclic appearance of extremely virulent strains that may cause widespread infection with high mortality, such as that of 1918, which infected 20% of the world's population and killed more people than World War I. What is this type of infection called?

Which of the following statements is FALSE regarding phage lambda as a temperate phage?

How is lambda phage being used to fight the problem of antibiotic resistance in bacteria?

The lymphocyte protein chemokine receptor 5 (CCR5) is involved in HIV. Functionally, CCR5 is a(n)

The pol open reading frame of HIV encodes

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

Molecular Regulation

Biotechniques and Synthetic Biology

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Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

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Food and Industrial Microbiology

Origins and Evolution

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

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Microbes in Global Elemental Cycles

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The Adaptive Immune Response

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Proteolysis of the influenza produces a fusion peptide, which initially binds to a glycoprotein on the host's cell membrane that serves as a receptor.