Question 1

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 2

Use the following information to answer the next few questions.
Poliovirus is a positive-sense RNA virus of the picornavirus group.At its 5' end,the RNA genome has a viral protein (VPg)instead of a 5' cap.This is followed by a nontranslated leader sequence,and then a single long protein coding region (~7000 nucleotides),followed by a poly-A tail.Observations were made that used radioactive amino acid analogues.Short-period use of the radioactive amino acids result in labelling of only very long proteins,while longer periods of labelling result in several different short polypeptides.
-What part of the poliovirus would first interact with host cell ribosomes to mediate translation?

Accepted Answer

A) the poly-A tail 
B) the leader sequence 
C) the VPg protein 
D) the AUG in the leader sequence 
E) the AUG at the start of the coding sequence 
A) the poly-A tail 
B) the leader sequence 
C) the VPg protein 
D) the AUG in the leader sequence 
E) the AUG at the start of the coding sequence

Question 3

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 4

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 5

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 6

RNA viruses require their own supply of certain enzymes because

Accepted Answer

A) host cells rapidly destroy the viruses. 
B) host cells lack enzymes that can replicate the viral genome. 
C) these enzymes translate viral mRNA into proteins. 
D) these enzymes penetrate host cell membranes. 
E) these enzymes cannot be made in host cells. 
A) host cells rapidly destroy the viruses. 
B) host cells lack enzymes that can replicate the viral genome. 
C) these enzymes translate viral mRNA into proteins. 
D) these enzymes penetrate host cell membranes. 
E) these enzymes cannot be made in host cells.

Question 7

What is the function of reverse transcriptase in retroviruses?

Accepted Answer

A) It hydrolyzes the host cell's DNA. 
B) It uses viral RNA as a template for DNA synthesis. 
C) It converts host cell RNA into viral DNA. 
D) It translates viral RNA into proteins. 
E) It uses viral RNA as a template for making complementary RNA strands. 
A) It hydrolyzes the host cell's DNA. 
B) It uses viral RNA as a template for DNA synthesis. 
C) It converts host cell RNA into viral DNA. 
D) It translates viral RNA into proteins. 
E) It uses viral RNA as a template for making complementary RNA strands.

Question 8

Use the figure that follows to answer the questions below.
  
-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

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 ~6300 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 10

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 would you use to determine if the agent is a prion?

Accepted Answer

A) I only 
B) II only 
C) III only 
D) IV only 
E) either I or IV 
A) I only 
B) II only 
C) III only 
D) IV only 
E) either I or IV

Question 11

Use the following information to answer the few questions.
The herpes viruses are very important enveloped DNA viruses that cause disease in all vertebrate species and in some invertebrates such as oysters.Some of the human ones are herpes simplex (HSV)I and II,causing facial and genital lesions,and the varicella-zoster (VSV),causing chicken pox and shingles.Each of these three actively infect nervous tissue.Primary infections are fairly mild,but the virus is not then cleared from the host; rather,viral genomes are maintained in cells in a latent phase.The virus can then reactivate,replicate again,and be infectious to others.
-In 2009,a flu pandemic was believed to have originated when viral transmission occurred from pig to human,thereby earning the designation,"swine flu." Although pigs are thought to have been the breeding ground for the 2009 virus,sequences from bird,pig,and human viruses were all found within this newly identified virus when isolated from humans.What is the most likely explanation of why this virus contained sequences from bird,pig,and human viruses?

Accepted Answer

A) The virus was descended from a common ancestor of bird, pig, and human flu viruses. 
B) The infected individuals happened to be infected with all three virus types. 
C) Related viruses can undergo genetic recombination if the RNA genomes mix and match during viral assembly. 
D) The human was likely infected with various bacterial strains that contained all three RNA viruses. 
E) The swine virus genomic sequences evolved to be similar to bird and human. 
A) The virus was descended from a common ancestor of bird, pig, and human flu viruses. 
B) The infected individuals happened to be infected with all three virus types. 
C) Related viruses can undergo genetic recombination if the RNA genomes mix and match during viral assembly. 
D) The human was likely infected with various bacterial strains that contained all three RNA viruses. 
E) The swine virus genomic sequences evolved to be similar to bird and human.

Question 12

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 13

The host range of a virus is determined by

Accepted Answer

A) the enzymes carried by the virus. 
B) whether its nucleic acid is DNA or RNA. 
C) the proteins in the host's cytoplasm. 
D) the enzymes produced by the virus before it infects the cell. 
E) the proteins on its surface and that of the host. 
A) the enzymes carried by the virus. 
B) whether its nucleic acid is DNA or RNA. 
C) the proteins in the host's cytoplasm. 
D) the enzymes produced by the virus before it infects the cell. 
E) the proteins on its surface and that of the host.

Question 14

The SARS outbreak in 2003 resulted in ________ deaths in Canada.

Accepted Answer

A) 8000 
B) 1026 
C) 438 
D) 44 
E) none 
A) 8000 
B) 1026 
C) 438 
D) 44 
E) none

Question 15

Which of the following represents a difference between viruses and viroids?

Accepted Answer

A) Viruses infect many types of cells, whereas viroids infect only prokaryotic cells. 
B) Viruses have capsids composed of protein, whereas viroids have no capsids. 
C) Viruses contain introns, whereas viroids have only exons. 
D) Viruses always have genomes composed of DNA, whereas viroids always have genomes composed of RNA. 
E) Viruses cannot pass through plasmodesmata, whereas viroids can. 
A) Viruses infect many types of cells, whereas viroids infect only prokaryotic cells. 
B) Viruses have capsids composed of protein, whereas viroids have no capsids. 
C) Viruses contain introns, whereas viroids have only exons. 
D) Viruses always have genomes composed of DNA, whereas viroids always have genomes composed of RNA. 
E) Viruses cannot pass through plasmodesmata, whereas viroids can.

Question 16

What is difference between an epidemic and a pandemic?

Accepted Answer

A) An epidemic is a disease; a pandemic is a treatment. 
B) An epidemic is restricted to a local region; a pandemic is global. 
C) An epidemic has low mortality; a pandemic has higher mortality. 
D) An epidemic is caused by a bacterial infection; a pandemic is caused by a viral infection. 
E) An epidemic spreads more quickly than a pandemic. 
A) An epidemic is a disease; a pandemic is a treatment. 
B) An epidemic is restricted to a local region; a pandemic is global. 
C) An epidemic has low mortality; a pandemic has higher mortality. 
D) An epidemic is caused by a bacterial infection; a pandemic is caused by a viral infection. 
E) An epidemic spreads more quickly than a pandemic.

Question 17

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 ~6300 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 18

What are examples of mobile genetic elements?

Accepted Answer

A) plasmids 
B) transposons 
C) viruses 
D) viruses and transposons only 
E) viruses, transposons and plasmids 
A) plasmids 
B) transposons 
C) viruses 
D) viruses and transposons only 
E) viruses, transposons and plasmids

Question 19

Use the following information to answer the next few questions.
Poliovirus is a positive-sense RNA virus of the picornavirus group.At its 5' end,the RNA genome has a viral protein (VPg)instead of a 5' cap.This is followed by a nontranslated leader sequence,and then a single long protein coding region (~7000 nucleotides),followed by a poly-A tail.Observations were made that used radioactive amino acid analogues.Short-period use of the radioactive amino acids result in labelling of only very long proteins,while longer periods of labelling result in several different short polypeptides.
-What conclusion is most consistent with the results of the radioactive labelling experiment?

Accepted Answer

A) The host cell cannot translate viral protein with the amino acid analogues. 
B) Host cell ribosomes only translate the viral code into short polypeptides. 
C) The RNA is only translated into a single long polypeptide, which is then cleaved into shorter ones. 
D) The RNA is translated into short polypeptides, which are subsequently assembled into large ones. 
E) The large radioactive polypeptides are coded by the host, whereas the short ones are coded for by the virus. 
A) The host cell cannot translate viral protein with the amino acid analogues. 
B) Host cell ribosomes only translate the viral code into short polypeptides. 
C) The RNA is only translated into a single long polypeptide, which is then cleaved into shorter ones. 
D) The RNA is translated into short polypeptides, which are subsequently assembled into large ones. 
E) The large radioactive polypeptides are coded by the host, whereas the short ones are coded for by the virus.

Question 20

Which of the following could use reverse transcriptase to transcribe its genome?

Accepted Answer

A) ssRNA 
B) dsRNA 
C) ssDNA 
D) dsDNA 
E) both dsDNA and dsRNA 
A) ssRNA 
B) dsRNA 
C) ssDNA 
D) dsDNA 
E) both dsDNA and dsRNA

Exam 19: Viruses

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

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?

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

RNA viruses require their own supply of certain enzymes because

What is the function of reverse transcriptase in retroviruses?

Use the figure that follows to answer the questions below. -Which of the three types of viruses shown above would you expect to include glycoproteins?

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?

The host range of a virus is determined by

The SARS outbreak in 2003 resulted in ________ deaths in Canada.

Which of the following represents a difference between viruses and viroids?

What is difference between an epidemic and a pandemic?

What are examples of mobile genetic elements?

Which of the following could use reverse transcriptase to transcribe its genome?

Introduction: Evolution and Themes of Biology

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

DNA Tools and 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 Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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