Microbiology Chapter 13

Animal viruses are divided into a number of families whose names end in -virus. -viridae. -viscous. -eieio.

-viridae.

The time from absorption to release for T-even phage is about 1 minute. 10 minutes. 30 minutes. 1 day.

30 minutes

Most phages that contain single-stranded DNA are extruded. contain a positive-sense DNA strand. have their DNA transformed to double-stranded DNA before replication and transcription occur. All of the choices are correct.

All of the choices are correct.

Once inside the host cell, phage DNA is replicated. is transcribed. may get degraded by bacterial nucleases. All of the choices are correct.

All of the choices are correct.

Regarding phage replication, the majority of phages are temperate. when integrated into host DNA, the phage DNA is called a prophage. lambda is a good example of a temperate phage. All of the choices are correct.

All of the choices are correct.

The nucleocapsid is composed of DNA and RNA and protein. DNA or RNA and protein. protein located in the nucleus. nucleic acid in the ribosome.

DNA or RNA and protein.

Which is a filamentous phage? M13 T4 lambda phi X174

M13

The family to which the Rhinovirus belongs is the Picornaviridae. Enterovirus. Enteroviridae. Picornavirus.

Picornaviridae.

What part of the E. coli T4 phage attaches to the host cell receptors? Capsid fragments around the nucleic acid. Protein fibers at the end of the phage tail. Pili of the envelope. Spikes of the envelope.

Protein fibers at the end of the phage tail.

One of the most intensively studied virulent phages which infects E. coli is T9. T4. beta. gamma.

T4

Diseases of short duration frequently followed by long-term immunity are referred to as intermittent infections. chronic infections. acute infections. persistent infections.

acute infections

Genetic exchange in segmented viruses that allows a zoonotic virus to infect humans is termed antigenic shift. hemagglutination. genetic reassortment. antigenic drift.

antigenic shift

Lysogenized cells are immune to any further infection by any virus. are immune to infection by the same virus. may have new properties. respond to infection with the SOS response. are immune to infection by the same virus AND may have new properties.

are immune to infection by the same virus AND may have new properties.

The correct order for the stages of a phage infection is: penetration, transcription, attachment, replication of nucleic acid and protein, assembly, release attachment, penetration, transcription, replication of nucleic acid and protein, assembly, release attachment, replication of nucleic acid and protein, penetration, transcription, assembly, release transcription, attachment replication of nucleic acid and protein, assembly, penetration, release

attachment, penetration, transcription, replication of nucleic acid and protein, assembly, release

Which does not refer to the shape of a virus? icosahedral (isometric) helical complex bacillus

bacillus

Transducing virulent phages do not lyse the cells they invade because transformation is taking place in the phage and this is transferred to the bacterium. bacterial DNA has replaced critical viral DNA in the phage. their virulence is dependent on the bacteria and virus replicating together. the lytic genes are unable to enter during penetration and are shed outside the host.

bacterial DNA has replaced critical viral DNA in the phage.

Viruses that infect bacteria are referred to as viralcidens. bacteriocidins. bacterialogens. bacteriophages.

bacteroiphages

In addition to lysis, animal viruses may exit the host cell by extrusion. budding. fission. fusion.

budding

The shape of the virus is determined by its nucleic acid. capsid. envelope. tail.

capsid

Once integrated, phage DNA can remain in the prophage state as long as the bacteria is frequently plated on new media. certain phage genes are excised. certain phage genes are repressed. bacterial repressor genes are activated.

certain phage genes are repressed.

Phage-encoded proteins are coded for by host DNA. coded for by phage DNA. proteins normally present in the uninfected cell. early proteins. coded for by phage DNA AND early proteins.

coded for by phage DNA AND early proteins.

A virion is a(n) pathogenic virus. subviral particle. complete, extracellular virus particle. enveloped virus particle.

complete, extracellular virus particle.

The changes that occur in virally-infected cells are characteristic for a particular virus and are referred to as the cytopathic effect. phenotypic effect. genotypic expression. cytology.

cytopathic effect.

If the infecting phage lacks some critical pieces of DNA necessary for replication it is called incomplete. mutated. defective. vegetative.

defective

Bacteriophages and animal viruses both may enter a host cell by endocytosis. both may enter a host cell by fusion. both involve entry of the entire nucleocapsid. differ because bacteriophages leave the capsid outside the cell, while animal virus entry involves the entry of the whole nucleocapsid.

differ because bacteriophages leave the capsid outside the cell, while animal virus entry involves the entry of the whole nucleocapsid.

Viruses are commonly referred to by their _________ name. locale genus disease species disease AND species

disease AND species

The common species name of the virus is based on the presence or absence of a nuclear membrane. type of nucleic acid it contains. disease the virus causes. geographic area it is found.

disease the virus causes

The replicative form of nucleic acid in filamentous phages is dsDNA. dsRNA. positive ssRNA. negative ssDNA.

dsDNA.

When an enveloped virus adsorbs to the host cell with its protein spikes, the virions are taken into the cell by the process of penetration. production. fusion. endocytosis.

endocytosis

The viral envelope closely resembles the prokaryotic cell wall. capsomere. eukaryotic cell membrane. cytoplasm.

eukaryotic cell membrane.

An exit method used by viruses which does not immediately destroy the host bacterium is lysis. inversion. extrusion. excising.

extrusion

The bacterial viruses that are released by a process termed extrusion are called lysogenic viruses. temperate phages. filamentous phages. lambda viruses.

filamentous phages.

The enveloped viruses typically obtain their envelope from the host plasma membrane. as they exit the host. from a newly constructed viral-derived membrane. from the nuclear membrane. from the host plasma membrane AND as they exit the host.

from the host plasma membrane AND as they exit the host.

Cells infected with animal viruses lyse because the release of the virions depletes the cell of energy. the virus releases enzymes that lyse the cell. functions necessary for cell survival are not carried out and the cell dies. the virus RNA and cellular protein interact to kill the cell.

functions necessary for cell survival are not carried out and the cell dies.

The receptors to which animal virus attachment proteins usually bind are proteins. carbohydrates. nucleic acid. lipids. glycoproteins.

glycoproteins

Enveloped viruses just require a stamp. have an outer lipid bilayer membrane containing various proteins. are surrounded by an additional layer of carbohydrate. envelope a cell.

have an outer lipid bilayer membrane containing various proteins.

The best known chronic infection involves chickenpox. herpes. hepatitis A. hepatitis B.

hepatitis B.

The integration of phage DNA into the bacterial chromosome occurs because of identical DNA sequences in both. the phage's ability to synthesize enzymes to enter the bacterium. similar RNA nucleotides in both. the similarity in enzyme metabolism. the phage's ability to synthesize enzymes to enter the bacterium AND similar RNA nucleotides in both.

identical DNA sequences in both.

Specialized transduction involves the random transmission of any gene. involves the transfer of a few specific genes. utilizes a defective virus. only involves genes near the viral DNA integration site. involves the transfer of a few specific genes, utilizes a defective virus AND only involves genes near the viral DNA integration site.

involves the transfer of a few specific genes, utilizes a defective virus AND only involves genes near the viral DNA integration site.

The protein coat of a virus is called a capsomere. is called a capsid. protects the nucleic acid. is involved in recognition of host cell receptors. is called a capsid, protects the nucleic acid AND is involved in recognition of host cell receptors.

is called a capsid, protects the nucleic acid AND is involved in recognition of host cell receptors.

Resistance of some animals to certain viral diseases is based on lack of spikes for attachment. phagocytosis of the virus by the host cell. the presence of the viral envelope. lack of specific receptors on the host cell.

lack of specific receptors on the host cell.

The phenomenon responsible for the ability of Corynebacterium diphtherium to produce the virulent toxin responsible for the devastating effects of diphtheria is called self-assembly. matrix conversion. prion protein. lysogenic conversion.

lysogenic conversion

Phages that can either replicate and cause cell lysis or can integrate their DNA into the host DNA are called lysogenic phages. lytic phages. virulent phages. segmented phages.

lysogenic phages.

In the region of budding, the inside of the plasma membrane becomes coated with enzymes. carbohydrates. steroids. matrix proteins.

matrix proteins

A temperate phage may be lysogenic. may be lytic. enters a lysogenic or lytic life cycle shortly after entering the host cell. are all RNA viruses. may be lysogenic AND enters a lysogenic or lytic life cycle shortly after entering the host cell.

may be lysogenic AND enters a lysogenic or lytic life cycle shortly after entering the host cell.

Carriers may have a persistent infection. may be a source of infection. usually show symptoms of the disease. have been cured of the infection. may have a persistent infection AND may be a source of infection.

may have a persistent infection AND may be a source of infection.

Assembly of the T4 phage may involve some self-assembly. may involve the use of scaffolds. is completely self-assembly. is completely dependent on scaffolds. may involve some self-assembly AND may involve the use of scaffolds

may involve some self-assembly AND may involve the use of scaffolds

Outside of living cells, viruses are scavenging glucose. slowly stockpiling ATP from the mitochondria. using cilia to move to the next host. metabolically inert.

metabolically inert.

DNA is protected from restriction enzymes by being sequestered in a lysosome. turned into RNA. methylated. made into double stranded RNA.

methylated

One group of animal viruses that are able to agglutinate red blood cells are the coronavirus. retrovirus. reovirus. myxovirus.

myxovirus

Using phages to treat a bacterial infection is an interesting idea because a single type of phage can destroy a wide range of strains of the same pathogen. of the increasing problem of antibiotic resistance. lysed bacteria pose no threat. a single phage can be genetically engineered to infect many different species of bacteria.

of the increasing problem of antibiotic resistance.

Filamentous phage only infect E. coli that have pili. only infect E. coli lacking pili. infect E. coli regardless of the presence of pili. do not infect E. coli.

only infect E. coli that have pili.

In latent infections, the virions are constantly produced. only produced during reactivation. produced slowly. continually being slowly budded out.

only produced during reactivation

An infection in which the virus is continually present in the body is referred to as acute. balanced. determinant. persistent.

persistent

A limiting factor for viral infection is internal metabolic temperature of the host cell. nutrition of the host cell. stage of cell cycle of the host cell. presence of specific receptor molecules on the host cell.

presence of specific receptor molecules on the host cell.

Viruses probably keep the numbers of bacteria in check. have no effect on the number of bacteria. increase the number of bacteria. are active in passing DNA from one bacterium to another. probably keep the numbers of bacteria in check AND are active in passing DNA from one bacterium to another.

probably keep the numbers of bacteria in check AND are active in passing DNA from one bacterium to another.

Phage-encoded enzymes are all produced simultaneously. produced in a sequential manner. strictly host enzymes. used to customize the cell for viral production. produced in a sequential manner AND used to customize the cell for viral production.

produced in a sequential manner AND used to customize the cell for viral production.

A virion is composed of lipid, protein, and either RNA or DNA. protein and either RNA or DNA. protein and both, RNA and DNA. protein, either RNA or DNA, and possibly lipid.

protein, either RNA or DNA, and possibly lipid.

During attachment of phage to E. coli, the phage actively seek out the bacteria. randomly bump into the bacteria. attach to proteins or carbohydrates on the bacterial surface. attach to the bacterial RNA. randomly bump into the bacteria AND attach to proteins or carbohydrates on the bacterial surface.

randomly bump into the bacteria AND attach to proteins or carbohydrates on the bacterial surface.

For which of the following processes are enzymes not required? replication translation maturation self-assembly

self-assembly

A key feature of all viral infections is the integration of viral DNA into host DNA. disintegration of host DNA. addition of a lipid membrane to the virus. separation of viral nucleic acid from the capsid.

separation of viral nucleic acid from the capsid.

The terms isometric, icosahedral and pleomorphic refer to viral life cycles. forms of nucleic acid. types of viral envelopes. shapes of viruses.

shape of viruses

The filamentous phages all contain single-stranded DNA. double-stranded DNA. single-stranded RNA. double-stranded RNA.

single-stranded DNA.

In the region of budding, the plasma membrane becomes involved with carbohydrates. spike proteins. matrix proteins. enzymes. spike proteins AND matrix proteins.

spike proteins AND matrix proteins.

Attachment of animal viruses to the host cell may be by means of a tail. the envelope. a capsid. spikes.

spikes

The protein projections on the surface of a virus that are involved in attachment to the host cell are called suckers. pili. cilia. spikes. hooks.

spikes

The genome of retroviruses is made of ssDNA. dsDNA. ssRNA. dsRNA.

ssRNA

In the replication of phage containing positive-sense DNA, the host's enzymes are used to make dsDNA. the host's DNA polymerase uses the phage RNA as a template to make negative-sense DNA. a phage-encoded DNA polymerase is used to make negative-sense RNA using the phage positive-sense RNA as a template. a phage-encoded DNA polymerase is used to make DNA using the phage positive-sense RNA as a template.

the host's enzymes are used to make dsDNA.

What part of the attached bacteriophage enters through the host cell wall? the entire virus only the enzymes necessary for replication the nucleic acid the nucleic acid and capsid the capsid only

the nucleic acid

During penetration of E. coli by the T4 phage lysozyme is used to allow entry of the phage capsid. the tail acts as a "hypodermic needle", injecting the phage DNA into the cell. the protein fibers digest a hole in the cell wall. the bacterial receptor molecules open a hole through the cell wall.

the tail acts as a "hypodermic needle", injecting the phage DNA into the cell.

Retroviruses are unique in that they replicate in nervous system cells. do not have a capsid. use RNA as a template to make DNA. use DNA as a template to make RNA.

use RNA as a template to make DNA

A phage that replicates inside the host cell and then lyses its host during its release is a virulent or lytic phage. latent phage. lysogenic phage. dormant phage.

virulent or lytic phage