Ch. 6 An Introduction to the Viruses
True or False: Hepatitis B virus is the common name while Hepadnavirus is the genus name
True
True or False: Inoculation of laboratory animals is an in vivo method of viral cultivation
True
True or False: Most active viral infections lead to cell death regardless of the type of release process
True
True or False: bacteriophages can increase the pathogenicity of their bacterial host
True
True or False: cancerous tissue conserve as a primary cell line for viral culture
True
True or False: chicken eggs have a mono layer of cells within them which offer a good place to propagate virus
True
True or False: viruses can contain either DNA or RNA, but not both
True
What term is used to specifically describe the types of viruses that infect bacteria?
bacteriophage
Plaques are associated with which of the following?
bacteriophage infection of bacteria
Which of the following is a common feature of continuous cell lines?
continuous growth
In the disease condition known as bovine spongiform encephalopathy, what does "bovine" mean?
cow
Multi nucleated cells, giant cell, and inclusion bodies are examples of __________________
cytopathic effects
Where are most RNA viruses replicated and assembled within the host?
cytoplasm
Identify all the types of nucleic acid genomes which have been discovered carried by various bacteriophages
dsRNA, ssRNA, dsRNA, ssDNA
Which term is used to describe the process when a viruses is engulfed by a cell in a vacuole or vesicle?
endocytosis
An ___________ virus has a membranous layer external to the nucleocapsid
enveloped
Viruses that specifically infect the bacterium Escherichia coli are known as T- _______ phages
even
Which of the following is NOT a sign of viral propagation in inoculated eggs?
formation of plaques
The total nucleic acid content of a virus can be referred to as the viral _____________
genome
__________ viruses have rod-shaped capsomers while the capsomers of ________________ viruses are arranged as a multifaceted polygan
helical, icosahedral
Which is true regarding viral nomenclature?
hepadnavirus is the genus name for the virus commonly called "hepatitis B virus"
The _________ range defines the limitations of the type of cell that a virus that can invade
host
Viral transformation implies
host DNA is changed
Capsid structure which has 20 panels of capsomers arranged in a symmetrical pattern is called
icosahedral
Which Latin phrase describes the cultivation or testing "in glass" or outside of a living organisms?
in vitro
Which of the following is a mass of viruses of damaged organelles due to the cytophathic effect of viral infection?
inclusion body
How does bacteriophage nucleic acid enter the host cell?
injection
The term ________ is used to describe the physical rupture of a cell
lyse
When a bacterium acquires a new trait from a temperate phage, ___________ conversion has occured
lysogenic
Identify any of the following which viroids do NOT have
metabolic pathways, envelope, capsid, and mitochondrion
Somatic human cells undergo ________ to produce new cells. (Hint: type of cell division)
mitosis
Somatic human cells undergo _________ to produce new cells
mitosis
Primary cells undergo which type of division to produce a mono layer for animal virus culture?
mitotic
Identify all the components of the nucleocapsid
nucleic acid and capsid
Most DNA viruses will assemble their virions within the host cells _________
nucleus
A _________ describes any virus that can lead to cancer
oncovirus
Identify which of the following are reliant on the viral capsid
penetration and adsorption
A cell harboring a virus that is not causing cytopathic effects is characteristic of which type of infection?
persistent infection
A ___________ is observed as a clear area where phage-infected bacterial cells cultivated agar have been disrupted
plaque
Which of the following would you expect to see from bacteriophage propagation?
plaques
Capsomers are composed of __________ (HINT: Is a macro molecule)
protein
Which of the following describe animal virus that has integrated its genome into the host cell's genome?
provirus
when it comes to virus multiplication, viral exocytosis refers to
release
Identify the commonalities between temperate phages and lytic phages
release, adsorption, biosynthesis of viral components, assembly, penetration
In some viruses, including HIV, the enzyme __________ __________ transcribes RNA into DNA
reverse transcriptase
Which of the following denotes the genus of Herpes simplex virus
simplexvirus
Which of the following viral structures must be specific for adsorption?
spike proteins
Most viral __________ is the capsid or envelope are composed of glycoproteins
spikes
Viral glycoproteins that protrude from the viral envelope and attach to host cells receptors are termed ___________
spikes
viruses are classified into families based on genetic makeup and ___________
structure
Which suffix represents a viral family?
viridae
A single virus particle is known as a ________
virion
Identify the smallest pathogenic agent
virion
Cell (tissue) culture is considered an "in ___________" method to propagate virus
vitro
In _________ is a latin phrase describing cultivation or testing within a living system.
vivo
A __________ is an infectious agent that lacks a capsid and merely consist of a strand of RNA
vivoid
Once a continuous cell line has grown and filled its container then
you can take a sample of the cells and place the cells into a new container
List the correct order of viral life cycle phases
1. absorption 2. penetration 3. uncoating 4. synthesis 5. assembly 6. release
The smallest virus is approximately what size?
20 nanometers
True or False: All non cellular infectious agents are morphologically similar to viruses.
False
True or False: Bacteriophages infect eukaryotic and prokaryotic microorganisms
False
True or False: The interior of eggs normally contains non-pathogenic bacterial flora but no viruses
False
True or False: the capsid of all viruses is protected by an external envelope
False
True or False: viruses which can lead to cancer are termed carcinoviruses
False
Rank smallest in size to largest in size
1. viruses 2. bacteria 3. human cells
Identify any of the following which can be used as primary cell lines
any of the answers listed here: embryonic tissue, adult tissue cells, fetal cell, cancer cells
Which structure immediately encloses viral nucleic acid?
capsid
Which viral structure can promote binding to a host cell?
capsid and envelope
A __________ is a protein subunit that forms the viral capsid
capsomer
The monomer of a capsid is called a ________
capsomer
Identify any of the following that could be considered an in vivo method of viral multiplication
chickens, chicken eggs, and mice
The word ___________ is used to describe viruses which have a non-icosahedral or non-helical arrangement of capsomer proteins
complex
Identify the virus types which are released from host cells by lysis
complex and naked
What is the typical route of infection for mad cow disease?
consumption of contaminated food
Identify all the methods that a virus can use to gain entry into an animal cell.
engulfment/ phagocytes of virus and fushion of the viral envelope and cell membrane
Two shapes of capsides are _________ and ___________, which is a type of polyhedran
helical and isosahedral
Through the process of _________, a prophage is activated and enters the lytic cycle
induction
__________ are infectious agents that infect only bacterial cells
phages
Which agent is the cause of spongiform encephalopahty?
prion
_______ is a name given to a disease-causing agent composed only of protein
prion
Transduction leads to which important consequence?
spread of drug resistance in bacteria
Which of the following are cytopathic effects in virally infected animal cells?
syncytia and giant cells
A ________ phage is bacteriophage that incorporates itself into the host genome as a lysogenic prophage
temperate
Which is not a reason that eggs provide an excellent in virus viral cultivation system?
the egg contains a tissue monolayer
Identify any of the following pathways which could produce proteins used by virus
viral positive --- ss RNA --> proteins used by viruses and host DNA ---> mRNA --> proteins used by viruses
Is it possible for a bacterial cell infected with a temperate phage to replicate?
yes
The acronym _______ is used for cytopathic effect
CPE
Reverse transcriptase is a performed viral enzyme that synthesizes the nucleic acid _______ from the nucleic acid _________
DNA and RNA
What is the term which describes a geometric viral from having 20 faces and 12 corners?
Icosahedron
True or False: Continuous cell lines grow more rapidly than original cell lines
True
True or False: Most virus are smaller than 0.2 mircons
True
Regarding enveloped viruses, at which point do viral spike proteins insert into the host's cell membrane in order to be incorporated into the new virion?
assembly
Which of the following describes the viral "parts" coming together to produce virions?
assembly
Identify which of the following are functions of the viral capsid or envelope?
assisting penetration of viral nucleic acid into the host cell and adherence to host cells
Two ways in which newly assembled viruses are released from host cells are through _________ or exocytosis by enveloped viruses, and through ________ by naked viruses
budding, lysis
At minimum, viruses are composed of nucleic acid and __________
capsid
CPE, or cytopathic effect, is one way to observe viral infection at the:
cellular level
Viruses ____________ depend on a host cells for replication
completely
Most bacteriophages have ________ - stranded DNA genomes
double
Most bacteriophages contain which types of nucleic acid?
dsDNA
Viral nucleic acids are
either single-stranded or double stranded
In which stage of viral multiplication would you expect to see "budding" occur?
release
Which best describes the shape of a helical virus?
spiral
Transmissible ___________ encephalopathy is a disease condition of the brain caused by an infection with prions
spongiform
Genes drug resistance can be transferred between bacteria via bacteriophages during the process of ________
transduction
The process where a virus transfers bacterial genes from another bacterial cell to another is called
transduction
____________ is when a phage transfers genes between bacteria
transduction
True or False: Cancerous tissue can serve as a primary cell line for viral cultures
true
The process of _________ occurs when viruses lose their envelope during penetration into a host cell or when the envelope/ capsid is are dissolved within a vacuole
uncoating
Which of the following is a TRUE statement?
viruses are smaller than yeast cells
Which of the following is completely composed of RNA?
vivoid
Which is the correct term to describe viral adherence to a host cell receptor?
adsorption
___________ is the viral process of attaching to the host cell receptor for the virus
adsorption
The ___________ cavity cushions and protects a developing bird embryo
amniotic
Identify prion related diseases
bavine spongiform encephalopathy and creutzfeldt-Jakab disease
In describing the release of mature enveloped viruses from host cells, the terms exocytosis and __________ are interchangable
budding
Which of the following viral release methods will not initially destroy the cell?
budding
mature enveloped viruses are released from host cells via __________ or exocytosis
budding
Which is closet in physical proximity to the nucleic acid of a virus?
capsid
Cell culture and _________ culture have the same meaning
tissue
List 3 purposes of viral cultivation
to identify viruses in clinical and specimens, to prepare vaccines, to study effects an host cells
Human bacteria that are lysogenized with phage may produce ________ that are harmful to the host
toxins
An antibiotic resistant bacterium is lysed by a phage infection which in turns releases a phage that gives antibiotic resistance to non-resistant cells this is called ________
transduction
A ____________ viruses does not have an envelope surrounding its capsid
naked
Capsids of ________ helical viruses are rigid and tight, while capsids of _________ helical viruses are flexible and loose
naked and enveloped
In __________ - sense RNA viral genomes, the RNA is not in a form ready for translation
negative
The term _______ is used to describe how some viruses burst cells during the release stage of viral multiplication
lysis
The process by which bacteriophages infect bacteria, conferring new traits enhancing human disease, is called __________
lysogenic conversion
Which of the following is NOT associated with Creutzfeldt-Jacob disease?
lysogenic conversion due to bacteriophages
____________ is the persistance of bacteriophage DNA within a host chromosome
lysogeny
the term __________ refers to the persistance of bacteriophages within host cells
lysogeny
Which of the following is used to describe the phage DNA that is latently incorporated into the bacterial host genome?
prophage
What is the primary function of the viral capsid and envelope?
protection
Which of the following best describes a prion?
proteinoceous infectous agent
At minimum, all viruses are composed of
proteins and nucleic acid
Which factor enables certain laboratory animals to propagate viruses more readily than others?
receptor specificity between and virus and particular animal hosts
HIV is described as a __________ because it synthesizes DNA from RNA using reverse transcription
retrovirus
The enzyme ____________ __________ is performed protein carried in by HIV responsible for converting its RNA genome into DNA
reverse transcriptase
viroids are composed of naked ______ strands
rna
What term is used to describe a virus type which depends on other viruses for replication?
satellite virus
