Microbiology Chapter 5

In this image, the virus labeled "A" is a(n) _______ virus.

naked

Capsids of _______ helical viruses are rigid and tight, while capsids of _______ helical viruses are flexible and loose

naked; enveloped

In _______-sense RNA viral genomes, the RNA is not in a form ready for translation.

negative

Which of the following terms is used to describe a viral RNA genome which CANNOT be immediately translated into protein?

negative-sense

Most DNA viruses will assemble their virions within the host cell's ______.

nucleus

All viruses must infect a host cell to replicate, and therefore, they are referred to as ________ intracellular parasites.

obligate

Viruses that are _______ lead to cancer in the infected hosts.

oncogenic

What term refers to a virus that can lead to cancer?

oncogenic virus

______ is the term for a virus that can cause tumors.

oncoviruses

Viruses have tropisms, that is they can infect

only cells of a certain tissue type

Which of the following best describes the relationship between viruses and their host cell?

parasitism

_______ infections are those in which cells are infected yet cells are not immediately lysed.

persistent

A(n) ______ is observed as a clear area where virus-infected monolayers of cells have been disrupted or destroyed.

plaque

Which of the following would you expect to see from bacteriophage propagation?

plaques

A(n) ______ is an infectious agent made up of only protein and associated with spongiform encephalopathies.

prion

Capsomers are composed of ______ . (hint it is a macromolecule)

proteins

A _______ is an animal virus which has integrated its DNA into the DNA of its host cell.

provirus

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

release

HIV is described as a(n) _______ because it synthesizes DNA directly from RNA using reverse transcriptase.

retrovirus

Which of the following is an enzyme found in HIV that is responsible for converting its RNA genome into a DNA genome?

reverse transcriptase

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

reverse transcriptase

When individual viral genes exist on separate pieces of genomic RNA, the genome is said to be ________.

segmented

On this diagram of a naked virus, the arrow indicates a(n) _______.

spike

What term is used to describe the viral proteins which protrude from the envelope and aid in attachment to host receptors?

spikes

Bovine _______ encephalopathy, or "mad cow disease," is a disease condition of the brain caused by an infection with prions.

spongiform

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

syncytium

Unlike cellular organisms, viruses are unable to

synthesize their own proteins

The human virome is

the complete set of viruses that are associated with the human body.

Viral transformation by oncogenic viruses implies:

the host cell is changed

A single virus particle could contain a genome consisting of

-RNA only -DNA only

Identify any of the following pathways which could produce proteins used by viruses.

-Viral positive-ssRNA- proteins used by viruses -Host DNA-mRNA- proteins used by viruses

The process of ________ occurs when viruses lose their capsid (and envelope, if they have one) during or after penetration into a host cell.

uncoating

Which of the following are cytopathic effect in virally infected animal cells?

-inclusion bodies -syncytia

Which of the following are cytopathic effects in virally infected animal cells?

-inclusion bodies -syncytia

At minimum, all viruses are composed of

-nucleic acids -proteins

In which of the following ways are enveloped animal viruses released from the host cell?

-release from the endoplasmic reticulum -bud off the cell membrane

List the correct order of viral life cycle phases

1) Adsorption 2) Penetration/ Uncoating 3) Synthesis 4) Assembly 5) Release

In this image of an enveloped virus, the component that is composed of nucleic acid is indicated by the letter _____.

A

Which is the correct term to describe viral adherence to a host cell receptor?

Adsorption

In this image of an enveloped virus, the component that is composed of lipids is indicated by the letter ______.

C

Viral nucleic acids are:

Either single-stranded or double stranded

Order the following microbes from smallest size to largest.

1) polio virus 2) streptococcus cell 3) yeast cell

True or false: Antibiotics are an effective treatment for most viral infections.

False

Viroids are composed of only naked _______.

RNA

What term is used to describe a virus type which depends on other viruses for replication?

Satellite virus

The virus shown here binding to host cell proteins is in the ______ stage of the viral life cycle.

adsorption

______ is the viral process of attaching to the host cell receptor for the virus.

adsorption

It is well known that ______ have no effect on treating viral infections.

antibiotics

Unlike organisms such as bacteria and protozoa, viruses

are not cellular

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 various viral "parts" coming together to produce virus particles?

assembly

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

capsomer

A(n) ________ is a protein subunit that forms the viral capsid.

capsomers

Which of the following would indicate that a virus is infecting a tissue culture cell line?

cells degenerate and lyse

When referring to a microbe that cannot reproduce, the term _______ is to bacteria as the term ________ is to viruses.

dead; inactive

The 2 principle processes by which viruses penetrate host cells are engulfment or ______ and direct fusion.

endocytosis

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

The total nucleic acid content of a virus can be referred to as the viral _______.

genome

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

genome

Most host cell receptors that viruses attach to are actually ______ that the cell uses in normal function

glycoproteins

The ______ range defines the limitations of the type of cell that a virus can invade.

host

Viruses which have symmetrical 20 sided capsids are called ________

icosahedral

A(n) _____ is a geometric viral form having 20 faces and 12 corners.

icosahedron

Viruses are best described as _______ rather than "dead".

inactive

_______ bodies are masses of viruses or damaged organelles of a cell due to a cytopathic effect of viral infection.

inclusion

A segmented RNA genome is one in which _______.

individual genes exist on separate pieces of RNA.

The viral envelope differs from the host cell membrane becaue

viral proteins replace host proteins

Which is most important for attachment of a virus to a host cell?

viral specificity for host receptors

A fully formed infectious virus particle in a host cell is often called a(n) ________

virion

The complete set of viruses that are associated with the human body is termed the human _________.

virome

Which of the following is true?

viruses are not cellular

Which of the following statements about treating viral diseases are correct?

-Antibiotics are not effective against viruses -Most vaccines target viral disease

Mature enveloped viruses are released from host cells via _____ or exocytosis.

budding

Positive-sense RNA is RNA that can be immediately

translated into protein

Typically, naked helical viruses are _____ flexible than enveloped helical viruses.

less

Both naked and complex viruses are released from the host cell via ______.

lysis

Viruses have fewer genes than bacteria because

they only need to redirect a cell's activity

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

transformation