micro chapter 13 learnsmart

In a lysogenized bacterium________ of the prophage results in a lytic infection

excision

A viral RNA genome that cannot be immediately translated into a protein is

- strand

Reverse transcriptase is a

RNA dependent DNA polymerase

Which protein is essential for maintenance of lysogenic state?

Repressor

When a virus gains entry to an animal cell by fusion, the viral envelope fuses with the

cytoplasmic membrane

True or False Some lysogenic phages can increase the pathogenicity of their bacterial host

true

The process by which the viral nucleic acid is released from the protective protein coat

uncaring

Before enveloped viruses bud from a host cell, specific viral proteins insert into the host membrane. These proteins become

viral spikes

infection of bacteria by this always ends with lysis of host cell

virulent phages

Lysogens are more suspectible to reinfection by the same type of phage true or false

false

Enveloped viruses can enter by

fusion or endocytosis

Physical rupture of a cell

lysis

Stage of viral multiplication at which budding occurs

release

Non-enveloped viruses cannot enter by fusion or since

they do not have a lipid envelope

Some viruses trigger _______ as a means of being released

apoptosis

The number of phage particles released from a host cell is called the

burst size

Early proteins expressed in the T4 lytic cycle is is an enzyme called . This enzyme degrades bacterial DNA

nuclease

which of the following describes a type of relationship that bacteriophages can have with their host?

productive lytic infection latent infection where host cell genotype is changed

Phage DNA that is latently integrated into bacterial host cell's genome is

prophage

Viruses that have an RNA genome and use the reverse transcriptase to synthesize a copy of the DNA of that genome are called

retroviruses

Phage DNA and proteins are made during the _____ stage of the T4 lytic cycle

synthesis

Enveloped viruses can derive their envelopes from

certain host organelles host cytoplasmic membranes

Retroviruses may lead to latent infections

they can integrate a DNA copy of their genome into the host chromosome

Double stranded RNA viruses carry their own replicase because the host cell cannot translate double stranded RNA true or false

true

Animal viruses can be infected by

-fertilized chicken egg -live animals -cell or tissue culture

True or False It is easier to cultivate animal viruses than bacteriophages

False. Animal viruses need animal cells or animals for cultivation

The molecules that viral spikes attach to on the host cell in order to gain entry are typically

Glycoproteins

how does bacteriophage nucleic acid enter the host cell?

Injection

Directs the incorporation of phage DNA into a bacterial chromosome

Integrase

A change in the phenotype of a lypsogen as a consequence of of the specific prophage it carries

Lysogenic conversion

Some single stranded RNA viruses have a ______ genome, which serves as MRNA

+ strand

Processes required for production of virus particles in host cells

-Replication of viral genome -Translation of viral genes -Transcription of viral genes

In which phage of the T4 phage lytic cycle are new phage particles put together?

Assembly

Replication of temperate phages and lytic phages have which steps in common?

Attachment, Release, Assembly, Genome Entry, Biosynthesis of viral components

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

Viral specificity for host receptors

Virally encoded polymerase needed for replication of RNA viruses is called

replicase

The accumulation of mutations that in genes that encode viral surface proteins recognized by the immune system results in a type of antigenic variation called

antigenic drift

When two different stains of a segmented virus enter the same cell, reassortment of the gene segments can occur, resulting in

antigenic shift