Microbiology Chapter 5

The term "naked" used in describing viruses implies the lack of

a lipid envelope

The viral process of attaching to the host cell receptor for the virus is called

adsorption

List the correct order of viral life cycle phases, starting with the first at the top

adsorption, penetrating/uncoating, synthesis, assemby, release

Which of the following describes the various viral "parts" coming together to produce virus particles

assembly

Identify the commonalities between temperate phages and lytic phages

assembly, biosynthesis of viral components, release, adsorption, penetration

Any virus that specifically infects bacteria is called

bacteriophage

plaques are associated with which of the following

bacteriophage infection of bacteria

During the release stage of the viral multiplication cycle, enveloped viruses leave their host cells through __________, or exocytosis.

budding

viruses carrying oncogenes in a host cell can result in

cancer

At minimum, viruses are composed of nucleic acid and a __________ comprised of protein

capsid

The structure directly surrounding the viral nucleic acid is the __________, a coat of proteins.

capsid

which is closest in physical proximity to the nucleic acid of a virus

capsid

Which of the following is considered a monomer (a single unit) of a capsid

capsomer

A protein subunit that forms the viral capsid is called a

capsomere

mad cow disease can be transmitted to humans through __________ of infected beef

consumption

in the condition known as bovine spongiform encephalopathy, what does "bovine" mean?

cow

most bacteriophages contain which type of nucleic acid

dsDNA

A single virus particle could contain a genome consisting of

either DNA or RNA but never both

which of these terms does not belong in this group

embryonic culture

Which term is used to describe the process in which a virus is engulfed by a cell and enclosed in a vacuole or vesicle

endocytosis

a virus that has a membranous layer external to the nucleocapsid is called an __________ virus

enveloped

True or false: the viral envelope and capsid are the same thing

false

true or false: the interior of eggs normally contains non-pathogenic bacterial cells but no viruses

false

comparing viral and bacterial genomes, viruses have __________ genes

fewer

Which of the following term describes the total nucleic content of a virus

genome

Which of the following is a term used to describe the different host cells which a virus can infect?

host range

A virus with a rod-shaped capsomer has a __________ capsid, while a virus with a capsid arranged as a multifaceted polygon has an __________ capsid

icosahedral

Masses of viruses or damaged organelles of a cell due to cytopathic effect of viral infection are called

inclusion

A segmented RNA genome is one in which

individual genes exist on separate pieces of RNA

a prophage is activated and enters the lytic cycle through the process called

induction

how does T-even bacteriophage nucleic acid enter the host cell?

injection

which of the following are in vivo methods for viral cultivation

inoculating chicken eggs with viruses; inoculation mice with viruses

identify all the components of the nucleocapsid

nucleic acid and capsid

At minimum, all viruses are composed of

nucleic acids and proteins

At minimum, all viruses are composed of:

nucleic acids and proteins

Viruses that lead to cancer in infected hosts are called

oncogenic

The term for a virus that can cause tumors is

oncovirus

Viruses have tropisms, that is they can infect

only cells of a certain tissue type

Infections in which cells harbor the virus but are not immediately lysed are called

persistent infections

which of the following describes the "clear" area where a virus-infected cell lysed and infected all the neighboring cells and lysed those too?

plaque

which of the following would you expect to see from bacteriophage propagation

plaques

single-stranded RNA genomes that are ready for immediate translation into proteins are called

positive-sense RNA

an infectious agent made up of only protein and associated with spongiform encephalopathies is a

prion

which agent is the cause if spongiform encephalopathy

prion

For the enveloped virus shown in the image, the arrow is pointing to to a

spike

a disease condition of the brain caused by an infection with prions is called bovine __________ encephalopathy or "mad cow disease"

spongiform

which of the following are cytopathic effects in virally infected animal cells

syncytia and inclusion bodies

Which of the following is a multinucleated mass of cells caused by viral infection

syncytium

unlike cellular organisms, viruses are unable to

synthesize their own proteins

Some deadly human pathogens such as diphtheria, cholera, and botulism are made more virulent by bacteriophages known as __________ phages, or prophages

temperate

What name is given to a phage "type" which can incorporate itself into the host genome as a lysogenic prophage?

temperate

a bacteriophage that does not immediately lyse or change the appearance of host cells is called a __________ phage

temperate

which type of phage generally can increase the pathogenicity of a bacterium

temperate phage

__________ phages enter the prophage state, while __________ phages burst the host cell

temperate; lytic

the uncoating step in a viral life cycle, where the genome is released from the capsid, is not required in a bacteriophage because __________

the phage genome is directly injected into the cell cytoplasm

two terms that have the same meaning are cell culture and __________ culture

tissue

list 3 purposes of viral cultivation

to prepare vaccines; identify viruses in clinical specimens; study effects on host cells

Which term describes the effect of an oncogenic virus on host cells

transformation

True or false: bacteriophages can increase the pathogenicity of their bacterial host

true

True or false: viral nucleic acid may be single-stranded or double-stranded DNA or RNA

true

true or false: bacteriophages can contain double-stranded DNA or single-stranded DNA or RNA

true

Which term describes the process of a virus losing its capsid (and envelope, if it has one) and exposing viral nucleic acids to the immediate environment?

uncoating

virus cultivation is an important activity because viral stocks are needed for the preparation of some

vaccines

the viral envelope differs from the host cell membrane because

viral proteins replace host proteins

Change in a cell line monolayer is indicative of which of the following?

virally infected cells

A type of virus that parasitizes other other viruses infecting the same host cell is called a

virophage

Which of the following is true regarding viruses

viruses are not cellular

Is it possible for a bacterial cell infected with a temperate phage to replicate

yes

Which of the following statements regarding protein synthesis is true

All viruses lack the machinery to to synthesize proteins

In viral multiplication, capsids and genetic material are packaged into virus particles during the __________ step.

Assembly

the initials used for cytopathic effects are

CPE

A __________ virus does not have an envelope surrounding its capsid

naked

an RNA genome that is not in a form ready for translation is called __________-sense RNA

negative

Lysogeny is best described as

integration of the viral genome into the host chromosome

viruses can cause cancer by

introducing oncogenes to a host cell and causing a loss of growth regulation

a bird egg containing an embryo is useful for cultivation of animal viruses because it

is a sterile environment and contains tissues that support viral multiplication

The term used to describe the physical rupture of a cell is

lysis

When a bacterium acquires a new trait from its temperate phage it is called

lysogenic conversion

when bacteriophages infect pathogenic bacteria resulting in a new pathogenic trait its called

lysogenic conversion

which of the following describes a process of bacteriophage infection which could result in a new disease trait (such as a toxin) in the infected bacterium

lysogenic conversion

The condition in which the bacterial host chromosome carries bacteriophage DNA is called

lysogeny

Which term refers to the persistence of bacteriophages within host cells

lysogeny

cultured cells grow in the form of a __________, a single, confluent sheet of cells that supports viral multiplication

monolayer

Which of the following is used to describe the phage DNA that is latently incorporated into the bacterial host genome?

prophage

toxins of the bacteria are responsible for diphtheria, cholera, and botulism are actually produced by

prophages

prions are composed entirely of what molecule

protein

Which macromolecule composes capsomers

proteins

Which of the following is the term for an animal virus that has integrated its DNA into the DNA of a host cell

provirus

which factor enables certain laboratory animals to propagate viruses more readily than others

receptor specificity between virus and particular animal hosts

In which stage of viral multiplication would you expect to see "budding" occur?

release

Because it synthesizes DNA directly from RNA using reverse transcriptase, HIV is described as a

retrovirus

in some viruses, including HIV, the enzyme ___________ ___________ transcribes RNA into DNA

reverse transcriptase