Question 1

Which of the following accounts for someone who has had a herpesvirus-mediated cold sore or genital sore getting flare-ups for the rest of his or her life?

Accepted Answer

A)  re-infection by a closely related herpesvirus of a different strain 
B)  re-infection by the same herpesvirus strain 
C)  co-infection with an unrelated virus that causes the same symptoms 
D)  copies of the herpesvirus genome permanently maintained in host nuclei 
E)  copies of the herpesvirus genome permanently maintained in host cell cytoplasm 
A)  re-infection by a closely related herpesvirus of a different strain 
B)  re-infection by the same herpesvirus strain 
C)  co-infection with an unrelated virus that causes the same symptoms 
D)  copies of the herpesvirus genome permanently maintained in host nuclei 
E)  copies of the herpesvirus genome permanently maintained in host cell cytoplasm

Question 2

Which of the following series best reflects what we know about how the flu virus moves between species?

Accepted Answer

A)  An avian flu virus undergoes several mutations and rearrangements such that it is able to be transmitted to other birds and then to humans. 
B)  The flu virus in a pig is mutated and replicated in alternate arrangements so that humans who eat the pig products can be infected. 
C)  A flu virus from a human epidemic or pandemic infects birds; the birds replicate the virus differently and then pass it back to humans. 
D)  An influenza virus gains new sequences of DNA from another virus, such as a herpesvirus; this enables it to be transmitted to a human host. 
E)  An animal such as a pig is infected with more than one virus, genetic recombination occurs, the new virus mutates and is passed to a new species such as a bird, the virus mutates and can be transmitted to humans. 
A)  An avian flu virus undergoes several mutations and rearrangements such that it is able to be transmitted to other birds and then to humans. 
B)  The flu virus in a pig is mutated and replicated in alternate arrangements so that humans who eat the pig products can be infected. 
C)  A flu virus from a human epidemic or pandemic infects birds; the birds replicate the virus differently and then pass it back to humans. 
D)  An influenza virus gains new sequences of DNA from another virus, such as a herpesvirus; this enables it to be transmitted to a human host. 
E)  An animal such as a pig is infected with more than one virus, genetic recombination occurs, the new virus mutates and is passed to a new species such as a bird, the virus mutates and can be transmitted to humans.

Question 3

Which of the following describes plant virus infections?

Accepted Answer

A)  They can be controlled by the use of antibiotics. 
B)  They are spread via the plasmodesmata. 
C)  They have little effect on plant growth. 
D)  They are seldom spread by insects. 
E)  They can never be passed vertically. 
A)  They can be controlled by the use of antibiotics. 
B)  They are spread via the plasmodesmata. 
C)  They have little effect on plant growth. 
D)  They are seldom spread by insects. 
E)  They can never be passed vertically.

Question 4

Use the following information to answer the questions below.
Some viruses can be crystallized and their structures analyzed. One such virus is Desmodium, or yellow mottle virus, which infects beans. This is a member of the tymovirus group and has a single-stranded RNA genome of ~6,300 nucleotides. Its virion is 25-30 nm in diameter, and is made up of 180 copies of a single capsid protein that self-associate to form each capsomere, which has icosahedral symmetry with 20 facets.
-If this virus has capsomeres with 20 facets, how many proteins form each one?

Accepted Answer

A)  1 
B)  5 
C)  ~6 
D)  ~20 
E)  ~180 
A)  1 
B)  5 
C)  ~6 
D)  ~20 
E)  ~180

Question 5

Use the following information to answer the following questions.
In 1971, David Baltimore described a scheme for classifying viruses based on how the virus produces mRNA.
The table below shows the results of testing five viruses for nuclease specificity, the ability of the virus to act as an mRNA, and presence (+) or absence (-) of its own viral polymerase.
  
-Based on the above table, which virus meets the requirements for a bacteriophage?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  E 
A)  A 
B)  B 
C)  C 
D)  D 
E)  E

Question 6

Use the following information to answer the questions below.
Some viruses can be crystallized and their structures analyzed. One such virus is Desmodium, or yellow mottle virus, which infects beans. This is a member of the tymovirus group and has a single-stranded RNA genome of ~6,300 nucleotides. Its virion is 25-30 nm in diameter, and is made up of 180 copies of a single capsid protein that self-associate to form each capsomere, which has icosahedral symmetry with 20 facets.
-In a cell-free system, what other components would you have to provide for this virus to express its genes?

Accepted Answer

A)  ribosomes, tRNAs and amino acids 
B)  ribosomes, tRNAs, amino acids, and GTP 
C)  RNA nucleotides and GTP 
D)  RNA nucleotides, RNA polymerase, and GTP 
E)  bean cell enzymes 
A)  ribosomes, tRNAs and amino acids 
B)  ribosomes, tRNAs, amino acids, and GTP 
C)  RNA nucleotides and GTP 
D)  RNA nucleotides, RNA polymerase, and GTP 
E)  bean cell enzymes

Question 7

Most human-infecting viruses are maintained in the human population only. However, a zoonosis is a disease that is transmitted from other vertebrates to humans, at least sporadically, without requiring viral mutation. Which of the following is the best example of a zoonosis?

Accepted Answer

A)  rabies 
B)  herpesvirus 
C)  smallpox 
D)  HIV 
E)  hepatitis virus 
A)  rabies 
B)  herpesvirus 
C)  smallpox 
D)  HIV 
E)  hepatitis virus

Question 8

-Which of the three types of viruses shown above would you expect to include glycoproteins?

Accepted Answer

A)  I only 
B)  II only 
C)  III only 
D)  I and II only 
E)  all three 
A)  I only 
B)  II only 
C)  III only 
D)  I and II only 
E)  all three

Question 9

Refer to the treatments listed below to answer the following questions.
You isolate an infectious substance that is capable of causing disease in plants, but you do not know whether the infectious agent is a bacterium, virus, viroid, or prion. You have four methods at your disposal that you can use to analyze the substance in order to determine the nature of the infectious agent.
I. treating the substance with nucleases that destroy all nucleic acids
and then determining whether it is still infectious
II. filtering the substance to remove all elements smaller than what can
be easily seen under a light microscope
III. culturing the substance by itself on nutritive medium, away from
any plant cells
IV. treating the sample with proteases that digest all proteins and then
determining whether it is still infectious
-Which treatment could definitively determine whether or not the component is a viroid?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  first II and then III 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  first II and then III

Question 10

A bacterium is infected with an experimentally constructed bacteriophage composed of the T2 phage protein coat and T4 phage DNA. The new phages produced would have

Accepted Answer

A)  T2 protein and T4 DNA. 
B)  T2 protein and T2 DNA. 
C)  a mixture of the DNA and proteins of both phages. 
D)  T4 protein and T4 DNA. 
E)  T4 protein and T2 DNA. 
A)  T2 protein and T4 DNA. 
B)  T2 protein and T2 DNA. 
C)  a mixture of the DNA and proteins of both phages. 
D)  T4 protein and T4 DNA. 
E)  T4 protein and T2 DNA.

Question 11

Use the following information to answer the following questions.
In 1971, David Baltimore described a scheme for classifying viruses based on how the virus produces mRNA.
The table below shows the results of testing five viruses for nuclease specificity, the ability of the virus to act as an mRNA, and presence (+) or absence (-) of its own viral polymerase.
  
-Given Baltimore's scheme, a positive sense single-stranded RNA virus such as the polio virus would be most closely related to which of the following?

Accepted Answer

A)  T-series bacteriophages 
B)  retroviruses that require a DNA intermediate 
C)  single-stranded DNA viruses such as herpes viruses 
D)  nonenveloped double-stranded RNA viruses 
E)  linear double-stranded DNA viruses such as adenoviruses 
A)  T-series bacteriophages 
B)  retroviruses that require a DNA intermediate 
C)  single-stranded DNA viruses such as herpes viruses 
D)  nonenveloped double-stranded RNA viruses 
E)  linear double-stranded DNA viruses such as adenoviruses

Question 12

Use the following information to answer the following questions.
In 1971, David Baltimore described a scheme for classifying viruses based on how the virus produces mRNA.
The table below shows the results of testing five viruses for nuclease specificity, the ability of the virus to act as an mRNA, and presence (+) or absence (-) of its own viral polymerase.
  
-Based on the above table, which virus meets the Baltimore requirements for a retrovirus?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  E 
A)  A 
B)  B 
C)  C 
D)  D 
E)  E

Question 13

Viral envelopes can best be analyzed with which of the following techniques?

Accepted Answer

A)  transmission electron microscopy 
B)  antibodies against specific proteins not found in the host membranes 
C)  staining and visualization with the light microscope 
D)  use of plaque assays for quantitative measurement of viral titer 
E)  immunofluorescent tagging of capsid proteins 
A)  transmission electron microscopy 
B)  antibodies against specific proteins not found in the host membranes 
C)  staining and visualization with the light microscope 
D)  use of plaque assays for quantitative measurement of viral titer 
E)  immunofluorescent tagging of capsid proteins

Question 14

A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants. Which of the following would be expected to occur?

Accepted Answer

A)  The plants would develop some but not all of the symptoms of the TMV infection. 
B)  The plants would develop symptoms typically produced by viroids. 
C)  The plants would develop the typical symptoms of TMV infection. 
D)  The plants would not show any disease symptoms. 
E)  The plants would become infected, but the sap from these plants would be unable to infect other plants. 
A)  The plants would develop some but not all of the symptoms of the TMV infection. 
B)  The plants would develop symptoms typically produced by viroids. 
C)  The plants would develop the typical symptoms of TMV infection. 
D)  The plants would not show any disease symptoms. 
E)  The plants would become infected, but the sap from these plants would be unable to infect other plants.

Question 15

In many ways, the regulation of the genes of a particular group of viruses will be similar to the regulation of the host genes. Therefore, which of the following would you expect of the genes of the bacteriophage?

Accepted Answer

A)  regulation via acetylation of histones 
B)  positive control mechanisms rather than negative 
C)  control of more than one gene in an operon 
D)  reliance on transcription activators 
E)  utilization of eukaryotic polymerases 
A)  regulation via acetylation of histones 
B)  positive control mechanisms rather than negative 
C)  control of more than one gene in an operon 
D)  reliance on transcription activators 
E)  utilization of eukaryotic polymerases

Question 16

Which of the following characteristics, structures, or processes is common to both bacteria and viruses?

Accepted Answer

A)  metabolism 
B)  ribosomes 
C)  genetic material composed of nucleic acid 
D)  cell division 
E)  independent existence 
A)  metabolism 
B)  ribosomes 
C)  genetic material composed of nucleic acid 
D)  cell division 
E)  independent existence

Question 17

Which viruses have single-stranded RNA that acts as a template for DNA synthesis?

Accepted Answer

A)  lytic phages 
B)  proviruses 
C)  viroids 
D)  bacteriophages 
E)  retroviruses 
A)  lytic phages 
B)  proviruses 
C)  viroids 
D)  bacteriophages 
E)  retroviruses

Question 18

-A linear piece of viral DNA of 8 kb can be cut with either of two restriction enzymes (X or Y). These are subjected to electrophoresis and produce the following bands:
 
Cutting the same 8 kb piece with both enzymes together results in bands at 4.0, 2.5, 1.0, and 0.5.
Of the possible arrangements of the sites given below, which one is most likely?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 19

Which of the following is the most probable fate of a newly emerging virus that causes high mortality in its host?

Accepted Answer

A)  It is able to spread to a large number of new hosts quickly because the new hosts have no immunological memory of them. 
B)  The new virus replicates quickly and undergoes rapid adaptation to a series of divergent hosts. 
C)  A change in environmental conditions such as weather patterns quickly forces the new virus to invade new areas. 
D)  Sporadic outbreaks will be followed almost immediately by a widespread pandemic. 
E)  The newly emerging virus will die out rather quickly or will mutate to be far less lethal. 
A)  It is able to spread to a large number of new hosts quickly because the new hosts have no immunological memory of them. 
B)  The new virus replicates quickly and undergoes rapid adaptation to a series of divergent hosts. 
C)  A change in environmental conditions such as weather patterns quickly forces the new virus to invade new areas. 
D)  Sporadic outbreaks will be followed almost immediately by a widespread pandemic. 
E)  The newly emerging virus will die out rather quickly or will mutate to be far less lethal.

Question 20

To cause a human pandemic, the H5N1 avian flu virus would have to

Accepted Answer

A)  spread to primates such as chimpanzees. 
B)  develop into a virus with a different host range. 
C)  become capable of human-to-human transmission. 
D)  arise independently in chickens in North and South America. 
E)  become much more pathogenic. 
A)  spread to primates such as chimpanzees. 
B)  develop into a virus with a different host range. 
C)  become capable of human-to-human transmission. 
D)  arise independently in chickens in North and South America. 
E)  become much more pathogenic.

Exam 19: Viruses

Which of the following accounts for someone who has had a herpesvirus-mediated cold sore or genital sore getting flare-ups for the rest of his or her life?

Which of the following series best reflects what we know about how the flu virus moves between species?

Which of the following describes plant virus infections?

Most human-infecting viruses are maintained in the human population only. However, a zoonosis is a disease that is transmitted from other vertebrates to humans, at least sporadically, without requiring viral mutation. Which of the following is the best example of a zoonosis?

-Which of the three types of viruses shown above would you expect to include glycoproteins?

A bacterium is infected with an experimentally constructed bacteriophage composed of the T2 phage protein coat and T4 phage DNA. The new phages produced would have

Viral envelopes can best be analyzed with which of the following techniques?

A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants. Which of the following would be expected to occur?

In many ways, the regulation of the genes of a particular group of viruses will be similar to the regulation of the host genes. Therefore, which of the following would you expect of the genes of the bacteriophage?

Which of the following characteristics, structures, or processes is common to both bacteria and viruses?

Which viruses have single-stranded RNA that acts as a template for DNA synthesis?

Which of the following is the most probable fate of a newly emerging virus that causes high mortality in its host?

To cause a human pandemic, the H5N1 avian flu virus would have to

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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