Chapter 13 Review
Which of the following statements regarding antigenic shift are true?
-little immunity to virus strains resulting from antigenic shift exists in the population. -viral strains resulting from antigenic shift contain RNA segments from different species. -antigenic shift results in a major change in the genetic composition of the virus
Which of the following are symptoms of influenza infection?
-muscle pain -headache -fever
Which of the following pairs is mismatched? 1. slow viral infection
...
Which of the following terms are not correctly matched? 1. Poxviridae
...
an infection lasting months or years 2. Latent viral infection: in inactive virus 3. Viroid
...
chickenpox 2. Picornaviridae
...
common cold 5. Flaviviridae
...
infectious mononucleosis 4. Picornaviridae
...
polio 3. Herpesviridae
...
An example of a latent viral infection is A. Cold sores. B. Smallpox. C. Subacute sclerosing panencephalitis. D. Influenza. E. None of the above.
A. Cold sores.
Cell lines that are derived from transformed (cancerous) cells are called A. continuous cell lines B. primary cell lines C. monolayers D. plaques E. embryonated
A. continuous cell lines
A persistent infection is one in which A. the disease process occurs gradually over a long period B. host cells are transformed C. viral replication is unusually slow D. host cells are gradually lysed E. the virus remains in equilibrium with the host without causing a disease
A. the disease process occurs gradually over a long period
What is the name of the process that involves both the release and the enveloping of the virus?
Budding
Which of the following can be used directly as messenger RNA?
+RNA
Which virus employs the use of an RNA-dependent RNA polymerase?
+RNA viruses
Predict which of the following would be outcomes of treatment with Tamiflu.
-an increase in the ability of the immune system to combat the infection -overall decrease in the replication rate of influenza -a decrease in the release of viral particles from the cell
Which of the following factors could have contributed to Barbara's development of shingles?
-her daughter and grandchildren moving into her house shortly after the death of her husband -her age, 68
What are some of the current challenges to production of the influenza vaccine?
-in order to yield a vaccine, the virus must be produced in eggs -the virus undergoes antigenic changes on a regular basis
Predict which of the following are reasonable outcomes of the cytokine storm during the 1918 flu pandemic.
-increased fluid in the lungs and labored breathing -an excessive inflammatory response leading to extensive tissue damage
Arrange the following statements in the order that best describes the sequence of events involved in the replication of influenza.
1. hemagglutinin spikes attach to host cells 2. influenza enters the host cell 3. nucleic acid enters the host cytoplasm 4. influenza proteins are synthesized 5. influenza nucleic acid is packaged in a capsid 6. influenza particles bud from the cell, releasing the virus into the surrounding environment
What is the correct sequence of events for the replication of a DNA virus?
1. virions attach to the host cells. 2. viral DNA is released into the nucleus of the host cell 3. enzymes required for multiplication of viral DNA are produced via transcription and translation 4. a copy of the DNA is made 5. capsid and other structural proteins are manufactured 6. virions are assembled to form complete viruses and are released from the host cell
In what year did Stanley Prusiner discover prions?
1982
What is the usual size range of viruses?
30 to 300 nm
The host DNA is usually degraded during which stage?
Biosynthesis
In which of the following is a true difference between viruses and bacteria? A. Viruses are not composed of cells. B. Viruses are filterable. C. Viruses divide by binary fission. D. Viruses don't have any nucleic acid. E. All of the above.
A.Viruses are not composed of cells.
Which of the following are possible strategies for treating viral infections? 1. blocking viral attachment to host cell receptors 2. blocking uncoating of the virus after entry 3. blocking insertion of viral DNA into the host cell chromosomes 4. blocking biosynthesis of viral nucleic acids. 5. all of the above
All of the above
In which stage does formation of mature viruses occur?
Assembly
The following steps occur during bacteriophage replication. What is the second step? A. Biosynthesis B. Penetration C. Attachment D. Lysis
B. Penetration
Which of these processes of viral multiplication is most likely to damage the host cell? A. Uncoating B. Release of nonenveloped viruses C. Reverse transcription of retroviral RNA D. Release of enveloped viruses E. Viral entry into host cells by fusion
B. Release of nonenveloped viruses
The following steps occur during biosynthesis of a + strand RNA virus. What is the third step? A. Synthesis of + strand RNA B. Synthesis of - strand RNA C. Penetration and uncoating D. Attachment E. Synthesis of viral proteins
B. Synthesis of - strand RNA
Which of the following pairs is mismatched? A. slow viral infection - an infection that lasts months or years B. viroid - infectious DNA C. prion - infectious protein D. latent viral infection - an inactive virus
B. viroid - infectious DNA
The potential use of viruses that infect bacteria to treat bacterial infections in humans is known as _______ ________
Bacteriophage therapy
What is the usual size range of viruses? A. 20 to 1000 um B. 20 to 1000 mm C. 20 to 1000 nm D. 20 to 1000 cm
C. 20 to 1000 nm
Prions cause disease by A. causing transcription and translation of abnormal proteins B. altering genes C. altering normal proteins D. reverse transcriptase
C. Altering normal proteins
Viruses possess genetic material comprised of A. protein only B. DNA and RNA C. DNA or RNA D. RNA only
C. DNA or RNA
The statement that best defines lysogeny is A. When the burst time takes an unusually long time. B. Lysis of the host cell due to a phage. C. Phage DNA is incorporated into host cell DNA. D. The period during replication when virions are not present. E. None of the above.
C. Phage DNA is incorporated into host cell DNA.
An envelope is acquired during which of the following steps? A. Penetration B. Uncoating C. Release D. Adsorption E. None of the above
C. Release
An oncogenic RNA virus must have which of the following enzymes? A. RNA polymerase B. Lysozyme C. Reverse transcriptase D. DNA-dependent DNA polymerase E. All of the above
C. Reverse transcriptase
How would you know that viruses were multiplying in a confluent lawn of E. coli on a solid culture medium? A. There would be small blue spots on the bacterial culture B. The bacterial culture would grow faster C. There would be small zones of clearing in the bacterial culture D. The bacterial colonies would swell
C. There would be small zones of clearing in the bacterial culture
Which of these factors is not used in classifying viruses? 1. Nucleic acid 2. Mode of replication 3. Morphology 4. Disease symptoms
Disease symptoms
All of the following are characteristics of viruses except A. viruses are non-cellular B. viruses are resistant to antibiotics C. viruses have nucleic acid surrounded by a plasma membrane D. viruses lack an ATP-generating mechanism E. viruses contain only one type of nucleic acid
C. viruses have nucleic acid surrounded by a plasma membrane
The protein coat of a virus is called the ________.
Capsid
Which of the following is not used for classification of viruses? A. Method of replication B. Size C. Nucleic acid D. Disease symptoms
D. Disease symptoms
Which of the following is necessary for replication of a prion? A. Lysozyme B. DNA C. DNA polymerase D. PSc E. RNA
D. PSc
A persistent infection is an infection in which A. Host cells are gradually lysed. B. The virus remains in equilibrium with the host without causing a disease. C. Host cells are transformed. D. The disease process occurs gradually over a long period. E. Viral replication is unusually slow.
D. The disease process occurs gradually over a long period.
In which of the following ways do viruses differ from bacteria? A. All of these options B. Viruses do not have nucleic acid C. Viruses are obligate intracellular parasites D. Viruses are not composed of cells E. None of these options
D. Viruses are not composed of cells
The preferred growth medium for most non-phage viruses is A. bacterial cells B. living animals C. embryonated eggs D. cell cultures E. agar plates
D. cell cultures
Shingles occurs after chickenpox because Human Herpesvirus-3 is A. oncogenic in a cell B. lytic in a cell C. slow in a cell D. latent in a cell
D. latent in a cell
Viruses possess genetic material comprised of ________. 1. protein only 2. DNA and RNA together 3. DNA only 4. DNA or RNA 5. RNA only
DNA or RNA
Which of the following is true regarding cultivation and isolation of animal viruses?
Diploid cell culture lines, developed from human embryos, are widely used for culturing viruses that require a human host
Which of the following is true concerning a lysogenic viral replication cycle?
During lysogeny, the viral genome integrates into the host DNA, becoming a physical part of the chromosome.
Viruses that have reverse transcriptase are in the A. Retroviridae and Picornaviridae. B. Influenzavirus. C. Bacteriophage families. D. Herpesviridae and Retroviridae. E. Hepadnaviridae and Retroviridae.
E. Hepadnaviridae and Retroviridae.
Which method cannot be used to culture viruses in a laboratory? A. Primates B. Tissue culture C. Live animals D. Embryonated eggs E. Nutrient agar culture media
E. Nutrient agar culture media
Viruses that possess a/an _____can penetrate the host cell by fusion.
Envelope
Which type of virus would produce viral glycoproteins to be expressed on the host cell membrane?
Enveloped viruses
A virion is an infectious fragment of "naked" RNA. T/F
False
Ebola virus is one of the smallest viruses that infects humans. T/F
False
The H5N1 avian influenza (bird flu) virus is readily spread from human to human T/F
False
Viruses can be grown only in living animal or plant hosts. T/F
False
Viruses range from 20 to 1000 nm in length and are easily seen using a compound light microscope. T/F
False
Which two viruses make DNA from an RNA template
Hepadnavirudae and retroviridae
All of the following are RNA viruses except ________. 1. poliovirus 2. HIV-1 virus 3. hepatitis B virus 4. togaviruses 5. rabies virus
Hepatitis B virus
We sometimes are able to generate antibodies (immune system proteins) that bind to and cover up some of the proteins on the outermost portion of a virus while it is in the bloodstream. This renders the virus unable to reproduce. Which step of viral replication are antibodies directly preventing
attachment
Drag each one of the labels onto the figure to identify the function of each structure.
LEFT SIDE TOP TO BOTTOM: -assists the virus in exiting the cell after reproduction -protects the viral nucleic acid -recognizes and attaches to host cells -contains antigenic determinants RIGHT SIDE: -contains the viral genetic information
Which of these viruses is known to cause a persistent viral infection? 1. varicellovirus 2. hepatitis A virus 3. Measles virus 4. herpes simplex virus
Measles virus
Barbara is worried about spending time with her grandchildren while being treated for shingles. Can her grandchildren contract chickenpox or shingles from spending time with their grandmother?
No. Because of their ages, the grandchildren have most likely been vaccinated against the chickenpox. They are also safe from contracting shingles because they are young.
How do normal prion proteins (PrP) differ from the infectious prion proteins?
Normal PrP have alpha-helices; infectious PrP have beta-pleated sheets.
Which method cannot be used to culture viruses in a laboratory?
Nutrient agar culture media
Viruses cable of inducing tumors are called _________ viruses
Oncogenic
Viruses are considered obligatory intracellular _________
Parasites
What is the second step of bacteriophage replication?
Penetration
The toxin production by Corynebacterium diptheriae carrying a temperate phage is an example of _______ _________.
Phage conversion
Which of these viruses can incorporate the molecule serving as mRNA into its capsid? 1. Poxvirus 2. Rhabdovirus 3. Picornavirus 4. Herpesvirus
Picornavirus
Infections agents known as ______ cause Creutzfeldt-Jakob disease (CJD)
Prions
How does the number of infectious prions increase?
Prions transform normal proteins into the misfolded beta-pleated sheet configuration; therefore, prions multiply by conversion
What is the name given to the viral DNA incorporated into a lysogenic cell?
Prophage
From which phrase is the term "prions" derived?
Proteinaceous infectious particles
Which of these enzymes is necessary for the replication of a + strand RNA virus? 1. DNA-dependent DNA polymerase 2. RNA-dependent RNA polymerase 3. DNA-dependent RNA polymerase 4. RNA-dependent DNA polymerase 5. reverse transcriptase
RNA dependent RNA polymerase
Which of these processes of viral multiplication is most likely to damage the host cell? 1. release of nonenveloped viruses 2. reverse transcription of retroviral RNA 3. viral entry into host cells by fusion 4. uncoating 5. release of enveloped viruses
Release of nonenveloped viruses
Viruses that use RNA as a template for transcribing DNA include ________. 1. Herpesviridae 2. Rhabdoviridae 3. Togaviridae 4. Picornaviridae 5. Retroviridae
Retroviridae
Which of the following viruses is transcribed from RNA to DNA to RNA during the replication cycle?
Retroviruses
Retroviridae use an RNA dependent DNA polymerase called _______ to transcribe DNA from an RNA strand.
Reverse transcriptase
A virus may contain any of any of the following except ________. 1. capsid proteins 2. spike proteins 3. ssRNA 4. lipid envelope 5. ribosomes
Ribosomes
Which disease did Stanley Prusiner first identify as being caused by prions?
Scrapie
An example of a latent virus infection is ________. 1. polio 2. measles 3. smallpox 4. shingles 5. influenza
Shingles
Members of the Adenoviridae cause ________.
The common cold
What happens to the packaged DNA of a specialized transduced phage when it infects a new recipient cell?
The host DNA integrates, with the prophage, into the new recipient chromosome
Poliovirus has a + strand RNA that acts as the messenger RNA T/F
True
Virus spikes are used for attachment to the host cell. T/F
True
Viruses are usually specific for particular cells of one host species. T/F
True
Why are the beta-pleated multimers of PrP potentially pathogenic?
The multimers are more stable and resistant to protease.
How does specialized transduction differ from regular lysogeny?
The prophage in specialized transduction carries with it pieces of the host chromosomal DNA.
How can specialized transduction contribute to the transfer of antibiotic resistance genes in a bacterial population?
The prophage takes an antibiotic resistance gene with it and is packaged with the newly synthesized viral DNA.
What would be the fate of a lytic bacteriophage if the host cell died prior to the assembly stage?
The virus would not be able to infect new hosts
How do naked viruses differ from enveloped viruses in their attachment/penetration phase?
Their nucleic acids are injected into the cell.
How would you know that viruses were multiplying in a confluent lawn of E. coli on a solid culture medium?
There would be small zones of clearing in the bacterial culture
How are prions different from other infectious agents?
They lack nucleic acid
How are viruses different from cells?
They require a host in order to reproduce.
What is the function of the structural elements of a virus?
To package and protect the viral genome
What disease does the human herpesvirus-1 cause?
cold sores or fever blisters
All of the following are oncogenic viruses except_________________. 1. varicellovirus 2. Human papillomavirus 3. HTLV 1 4. Hepatitis B virus
Varicellovirus
A viroid is A. A capsid without a nucleic acid. B. A naked
infectious piece of RNA. C. A complete, infectious virus particle. D. A provirus. E. None of the above.,B. A naked, infectious piece of RNA.
During the bacteriophage lysogenic cycle
________.,Phage DNA is inserted into the host chromosomes
To what does the term viral species refer?
a group of viruses sharing the same genetic information and structure
Prions cause disease by_____________
altering normal proteins
The normal function of the PrP protein in mammals is believed to be:
assisting in normal synaptic development and function.
Which of these statements is not true? 1. Attachment of animal viruses to host cells is random and nonspecific. 2. Animal viral DNA that is integrated into the host chromosome is called a provirus. 3. Enveloped viruses are released from the cell by budding. 4. Penetration of enveloped viruses can occur by a process called fusion. 5. Uncoating can occur due to host cell lysosome action.
attachment of animal viruses to host cells in random is random and nonspecific
structurally
bacteriophages are complex viruses. T/F,True
All of the following are characteristics of viruses except________________ 1. Viral nucleic acid is surrounded by a plasma membrane 2. Viruses are resistant to antibiotics 3. Viruses have either DNA or RNA as their nucleic acid
but not both 4. Viruses lack an ATP generating mechanism,Viral nucleic acid is surrounded by a plasma membrane
Some viruses have a membrane-like structure on their surface
composed of lipids, proteins, and carbohydrates. This is called a/an ________.,Envelope
Cell lines derived from transformed (cancerous) cells are called ________.
continuous cell lines
Prion diseases can be acquired in all of the following ways except by ________. 1. direct contact 2. inherited 3. transplantation 4. ingestion 5. contaminated surgical instruments
direct contact
A double-stranded
enveloped DNA virus that contains reverse transcriptase belongs to which family?,Hepadnaviridae
Assume you have isolated an unknown virus. It is a single-stranded RNA
enveloped virus. To which group does it most likely belong? A. Picornavirus B. Retrovirus C. Togavirus D. Herpesvirus E. None of the above,C.Togavirus
What is the preferred method for cultivating many animal viruses?
growing them on animal cell cultures
During the lysogenic cyle of the bacteriophage lambda
integrated phage DNA is known as the ______________,Prophage
Shingles occurs after chickenpox because human herpes virus-3 (HHV-3) is ________________
latent in a cell
The first step in biosynthesis of rhabdoviruses
negative-stranded RNA viruses, is to produce ________.,mRNA from an RNA template
To which group does a small
nonenveloped single-stranded RNA virus most likely belong? A. Togavirus B. Herpesvirus C. Retrovirus D. Picornavirus E. None of the above,D. Picornavirus
In which stage is the viral DNA introduced into the cell?
penetration
hepatitis
poxviridae:chickenpox
Enveloped viruses have a layer of lipids surrounding their capsid. This envelope is made mostly of host cell membrane. In which step does the virus acquire this envelope?
release
During the bacteriophage lysogenic cycle A. phage DNA is inserted into the host chromosome B. the burst time is shortened C. no attachment occurs D. new phage DNA is synthesized E. the host cell lyses
releasing new virions,A. Phage DNA is inserted into the host chormosomes
Which of the following best describes Barbara's condition?
shingles caused by the herpes zoster virus
Some plant diseases are caused by _______
short fragments of naked RNA.,Viroids
How could a virus pick up a human oncogene?
specialized transduction
What occurs during viral uncoating?
the capsid breaks apart, releasing the viral genome
During the maturation of enveloped viruses
the envelop is acquired through budding from the host cell membrane. T/F,True
In polio virus replication
the function of the antisense (- strand) RNA is to ________.,serve as a template for the production of sense (+strand) RNA
During lysogency
the phage remains latent T/F,True
When viruses infect cell cultures
they often the produce damage to the cells called _______ ________,Cytopathic effect
What type of infectious agent causes potato spindle tuber disease? 1. Rhabdovirus 2. Viroid 3. Prion 4. Virino
viroid
infectious DNA 4. Prion: infectious protein
viroid: infectious DNA
After attachment and entry into a host cell
what is the next step in the multiplication of animal viruses? A. Transcription of "late" genes B. Release C. Transcription of "early" genes D. Uncoating E. Synthesis of capsid proteins,D. Uncoating
After the attachment and entry of a virus into a host cell
what is the next step in the multiplication of animal viruses?,uncoating
Cauliflower mosaic virus is a double-stranded nonenveloped DNA virus like the smallpox virus. Knowing this
you can conclude that ________.,these two viruses are in the same family
