Ch. 5 Viruses Learn smart

Lysogeny is best described as:

integration of the viral genome into the host chromosome

When bacteriophages infect pathogenic bacteria resulting in new pathogenic trait its called _____

lysogenic conversion

Azidothymidine is an antiviral drug used to treat which viral stage

synthesis

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

-Syncytia -inclusion bodies

List the 3 purposes of viral cultivation

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

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

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

The suffix ____ is used to designate a viral family, while the suffix _____ is used to designate a viral genus.

-Viridae/ Virus

What facts best support the position that viruses are not living organisms?

-Viruses dont have any means of independent metabolism -viruses cannot reproduce on their own

List the correct order of viral life cycle phases

-adsorption -penetration/uncoating -synthesis -assembly -maturation -release

What can viruses NOT do

-consume food -replicate outside of a cell

Identify the commonalities between temperate phages and lytic phages

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

What cellular organisms can viruses infect?

-protozoa -bacteria -animals -plants fungi

Identify all the types of nucleic acid genomes which have been discovered carried by various bacteriophages

-ssRNA -ssDNA -dsDNA -dsRNA

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

Adsorption

Viruses were discovered by:

using a filter

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

Antibiotics

Unlike organisms such as bacteria and protozoa, viruses:

Are not cellular

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

Assembly

A type of virus that specifically infects bacteria is called a(n) ______

Bacteriophage

How many cases of viral infection occur worldwide annually?

Billions

Exocytosis, or _____, or enveloped viruses occurs from the host cell membrane during the release stage of the viral multiplication cycle

Budding

In which way do enveloped viruses leave their host cells?

Budding

Mature enveloped viruses are released from host cells via ____ or exocytosis

Budding

The acronym ____ is used for cytopathic effect.

CPE

At minimum, viruses are composed of nucleic acid and a _______ comprised of proteins

Capsid

Which structure immediately encloses viral nucleic acid?

Capsid

The arrow is pointing to a bacteriophage component called ___

Capsid head

What do Viroids Not have:

Capsid, mitochondrion, envelope, metabolic pathways

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

Capsomer

The monomer of a capsid is called a _____

Capsomer

Viruses _______ depend on a host cell for replication

Completely

Which is the typical route of infection for mad cow disease?

Consumption of contaminated food

Most RNA viruses will assemble the virion within the host cell's ____

Cytoplasm

Reverse transcriptase is a preformed viral enzyme that synthesizes the nucleic acid ____ from the nucleic acid ____

DNA;RNA

Viral DNA polymerase genes are expressed during the ____ stage of the synthesis phase of the viral life cycle

Early

Chicken ______ have a monlayer of cells within them which offer a good place to propagate virus.

Eggs

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

Endocytosis

Naked viruses do not possess a(n) ________

Envelope

Which term is used to describe the phospholipid bilayer found surrounding the capsid of some viruses?

Envelope

True or false: 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

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

Glycoprotein

Viruses with a ______ capsid have a rod-shaped capsomers, while the capsomers of viruses with ______ capsids are arranged as a multifaceted polygon.

Helical; icosahedral

What term is used to describe the different host cells which a virus can infect?

Host range

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

Icosahedron

If the term "dead" is used to describe a particular bacterial cell, then the term ______ would be used to describe a virus in a similar condition.

Inactive

Viruses are best described as ______ rather than "dead"

Inactive

Through the process of _____ , a prophage is activated and enter the lytic cycle

Induction

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

Less

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

Lyse

The term_____ (meaning rupturing) is used to describe how some viruses burst cells during the release stage of viral multiplication

Lysing

_____ is the persistence of bacteriophage DNA within a host chromosome

Lysogeny

What is the common name of bovine spongiform encephalophathy

Mad cow disease

A _______ virus does not have an envelope surrounding its capsid

Naked

what is the size unit that is best applied to viruses?

Nanometer

Which of the following terms is used to describe a viral RNA genome which cannot be immediately translated in protein

Negative-sense

The ________ refers to the capsid and the nucleic acid of a virus

Nucleocapsid

Viruses that are ______ lead to cancer in infected hosts

Oncogenic

____ is the term for a virus that can cause tumors

Oncovirus

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

Pathogens

_____ infections are those in which cells are infected yet cells are not immediately lysed

Persistent

The word "virus" comes from the latin word for _______

Poison

A(n) _____ is a proteinaceous infectious agent associated with spongiform encephalopathies

Prion

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

Prophage

86. Capsomers are composed of _____ (hint: it is a macromolecule)

Protein

What is the best description of a prion?

Proteinaceous infectious agent

Prions are composed entirely of what molecules?

Proteins

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

Provirus

Viroids are composed of naked ____ strands

RNA

Viroids are composed or only naked ______

RNA

The virus buds off the membrane and picks up an envelope and spike in the _________ stage of the viral life cycle.

Release

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

Retrovirus

An enzyme capable of taking an RNA fenome and generating a DNA copy is called

Reverse transcriptase

Some laboratory animals can propagate viruses in the laboratory more readily than others because many viruses exhibit host ______

Specificity

Transmissible ______ encephalophathy is a disease condition of the brain caused by an infection with prions

Spongiform

Which of the following diseases are caused by prions

Spongiform encephalophathy

what is the purpose of vaccines

Stimulate host immune system

Viruses are classified based on genetic make up, chemical composition, and ______

Structure

_________ occur when a virus induces multiple cells to fuse, making a large multinucleated cell.

Syncytia

A ______ phage is a bacteriophage that incorporates itself into the host genome as a lysogenic prophage

Temperate

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

Temperate

Viral transformation by oncogenic viruses implies:

The host cell is changed

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

True

True or false: most viral infections do not result in death of the host organism

True

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

True

True or false: viruses can contain either DNA or RNA but not both

True

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

Uncoating

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

Viral specificity for host receptors

Change in a cell line monolayer is indicative of what?

Virally infected cells

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

Virion

What is completely composed of RNA?

Viroid

Identify the smallest pathogenic agent

Virus

What does "obligate" mean in regards to viruses?

Viruses must have a host cell

What is true about viruses?

all Viruses lack the machinery to synthesize proteins

Embryonic eggs:

are completely sterile

Plaques are associated with what?

bacteriophage infection of bacteria

The process of ________, a type of penetration, occurs when viruses are taken into the cell followed by engulfment in a vacuole or vesicle.

endocytosis

Identify the virus types which are released from the host cells by lysis

-Complex -Naked

How does T-even bacteriophage nucleic acid enter the host cell

Injection

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

Yes