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