Chapter 6 MICRO (Unit 3)
At a minimum, a viral genome must include genes for
-regulating the actions of the host cell -packaging the mature virus particles -synthesizing the viral capsid
which are the three main criteria used in classifying viruses into families?
-structure -chemical composition -similarities in genetic makeup
the smallest animal virus, parvovirus, is approximately what size?
20 nanometers
a single virion could contain a genome of _______.
DNA only RNA only
Viral nucleic acids are
Either single-stranded or double stranded
Identify any of the following which can be used as primary cell lines adult tissues embryonic tissue fetal cells cancer cells
all of the above
embryonic eggs;
are completely sterile
Most cell lines used to propagate virus are
cancerous cells
the structure directly surrounding the viral nucleic acid is the ______, a coat of proteins
capsid
a ____ is a protein subunit that forms the viral capsid
capsomere
Which term is used to describe the phospholipid bilayer found surrounding the capsid of some viruses?
envelope
An _____ virus has a membranous layer external to the nucleocapsid
enveloped
(T/F) the viral envelope and capsid are the same thing
false
the total nucleic acid content of a virus can be referred to as the viral ______.
genome
two shapes of viral capsids are ________, which resembles a bracelet; or ____, which is a type of polyhedron
heical; icosahedral
identify the different environments in which some viruses can replicate
human bacterial animal
capsid structure which has 20 panels of capsomers arranged in a symmetrical pattern is called an _____
icosahedron
Which Latin phrase describes the cultivation or testing within a living organism?
in vivo
(T/F) typically, naked helical viruses are ____ flexible than enveloped helical viruses
less
Which four of the following are not found in viroids? capsid nucleic acid metabolic pathways envelope mitochondrion
metabolic pathways mitochondria envelope capsid
the largest known virus, the ___, is larger than some bacteria and visible in a light microscope
mimvirus
primary cells undergo which type of division to produce a monolayer for animal virus culture?
mitotic
a ____ virus does not have an envelope surrounding its capsid
naked
most viruses are on the order of what size unit?
nanometer
at minimum, all viruses are composed of
nucleic acids and proteins
the ____ refers to the capsid and nucleic acid of a nonenvelop virus
nucleocapsid
An ____ is observed as a clear area where phage-infected bacterial cells cultivated on agar have been disrupted
plaque
an ____ is a proteinaceous infectious agent associated with spongiform encephalopathies
prion
Prions are com posed of what molecule?
protein
Which marcomolecule composes capsomeres?
proteins
(T/F) cancerous tissues can serve as a primary cell line for viral culture
true
(T/F) embryonic tissue can serve as a primary cell line for viral culture
true
(T/F) inoculation of laboratory animals is an in vivo method of viral cultivation
true
(T/F) viroids are composed of just naked RNA
true
Viruses can contain either DNA or RNA, but not both
true
a single viral particle is referred to as a ______
virion
identify the smallest pathogenic agent
virion
the sum total of the viruses associated with your body is called the _______.
virome
order the following entities by average size, smallest to largest yeast cell virus bacterial cell
virus bacterial cell yeast cell
the latin term "in______" describes the cultivation or testing "in glass" or outside of a living organism
vitro
what term is used to describe a virus type which depends on other viruses for replication?
satellite virus
when an enveloped virus buds off the cell membrane, the membrane differs ____ from the host cell's membrane
significantly
viral glycoproteins that protrude from the viral envelope and attach to host cell receptors are termed ____________.
spikes
transmissible _____ encephalopathy, such as BSE, is a disease condition of the brain caused by an infection with prions
spongiform
which is NOT a reason that eggs provide an excellent in vivo viral cultivation system?
the egg contains a tissue monolayer