Microbiology Ch. 5- Exam 2

Host cells of viruses include ________. A) humans and other animals B) plants and fungi C) bacteria D) protozoa and algae E) All of the choices are correct

All of the choices are correct

The primary purpose of viral cultivation is ________. A) to isolate and identify viruses in clinical specimens B) to prepare viruses for vaccines C) to do detailed research on viral structure, lifestyle, genetics, and effects on host cells D) All of the choices are correct

All of the choices are correct

Uncoating of viral nucleic acid ________. A) does not occur in bacteriophage multiplication B) involves enzymatic destruction of the capsid C) releases viral nucleic acid into the cell D) occurs before replication E) All of the choices are correct

All of the choices are correct

Viral nucleic acids include which of the following? A) Double-stranded DNA B) Single-stranded DNA C) Double-stranded RNA D) Single-stranded RNA E) All of the choices are correct

All of the choices are correct

Which of the following is a type of cytopathic effect? A) Inclusions in the nucleus B) Multinucleated giant cells C) Inclusions in the cytoplasm D) Cells change shape E) All of the choices are correct.

All of the choices are correct.

Which of the following will not support viral cultivation? A) Live lab animals B) Embryonated bird eggs C) Primary cell cultures D) Continuous cell cultures E) All of the choices will support viral cultivation

All of the choices will support viral cultivation

Which of the following is incorrect about prophages? A) Present when the virus is in lysogeny B) Formed when viral DNA enters the bacterial chromosome C) Replicated with host DNA and passed on to progeny D) Cause lysis of host cells E) Occur when temperate phages enter host cells

Cause lysis of host cells

Reverse transcriptase synthesizes ________. A) the positive RNA strand from a negative RNA strand B) a negative RNA strand from a positive RNA strand C) RNA from DNA D) DNA from RNA E) None of the choices are correct

DNA from RNA

Which of the following is not a characteristic of a transformed cell? A) Viral nucleic acid integrated into host DNA B) Decreased growth rate C) Alterations in chromosomes D) Changes in cell surface molecules E) Capacity to divide indefinitely

Decreased growth rate

Which of the following is not associated with every virus? A) Envelope B) Capsomeres C) Capsid D) Nucleic acid E) Genome

Envelope

A specific animal virus has the ability to attach to and enter almost any animal host cell.

FALSE

An ideal antiviral drug would be one that killed the host cell, effectively preventing the virus from replicating.

FALSE

Glycoprotein spikes are essential for mediating the release stage of the viral life cycle.

FALSE

The adeno-associated virus (AAV) is a prion.

FALSE

Viruses are not filterable.

FALSE

Viruses are ultramicroscopic because they range in size from 2 mm to 450 mm.

FALSE

Who developed a rabies vaccine by separating bacteria from virus using a filter? A) Leeuwenhoek B) Koch C) Pasteur D) Cohn E) Semmelwise

Pasteur

A fully formed virus that can cause an infection in a host cell is called a virion.

TRUE

It is necessary to culture viruses both in vivo and in vitro so that vaccines can be developed, analysis of viral genomes can be made and viruses in clinical specimens can be identified.

TRUE

Prophages can be activated into viral replication and enter the lytic cycle.

TRUE

Spikes are glycoproteins of the virus capsid.

TRUE

Viral spikes are inserted into the host cell membrane before budding or exocytosis

TRUE

Viruses are simple, noncellular, and lack ribosomes.

TRUE

Viruses are the most common cause of acute infections that do not result in hospitalization.

TRUE

Viruses are unable to multiply outside of a host cell.

TRUE

Viruses are used to produce vaccines for prevention of certain viral infections

TRUE

Viruses mutate and some have not been discovered.

TRUE

When a virus enters a host cell, the viral genes redirect the genetic and metabolic activities of the host cell.

TRUE

What type of phage enters an inactive prophage stage? A) Primary B) Secondary C) Temperate D) Temporary E) Transformed

Temperate

Which of the following is not a typical capsid shape? A) Tetrahedral B) Complex C) Helical D) Icosahedron E) All of the choices are capsid shapes.

Tetrahedral

Which of the following is not true regarding the structure and function of viral spikes? A) They are found on both enveloped and naked viruses B) They are coded for by the host genome C) They are coded for by the viral genome D) They mediate the docking process of virus to host cell E) They consist of proteins and carbohydrates

They are coded for by the host genome

All of the following pertain to virus envelopes except ________. A) gained as a virus leaves the host cell membrane B) are comprised primarily of lipids C) contain special virus proteins D) help the virus particle attach to host cells E) are located between the capsid and nucleic acid

are located between the capsid and nucleic acid

Viruses that infect bacteria are specifically called ________. A) viroids B) prions C) bacteriophages D) satellite viruses E) All of the choices infect bacteria

bacteriophages

Viruses ________. A) cannot be seen in a light microscope B) are prokaryotic C) contain 70S ribosomes D) undergo binary fission E) All of the choices are correct

cannot be seen in a light microscope

A(n) ________ is the protein shell around the nucleic acid core of a virus. A) capsomere B) capsid C) spike D) envelope E) monolayer

capsid

Helical and icosahedral are terms used to describe the shapes of a virus ________. A) spike B) capsomere C) envelope D) capsid E) core

capsid

Virus capsids are made from subunits called ________. A) envelopes B) spikes C) capsomeres D) prophages E) peplomers

capsomeres

A common method for cultivating viruses in the lab is to use in vitro systems called ________ cultures. A) embryo B) cell C) plaque D) bacteriophage E) egg

cell

Persistent viruses that can reactivate periodically are ________. A) chronic latent viruses B) oncoviruses C) syncytia D) inclusion bodies E) cytopathic

chronic latent viruses

Viral genetic studies, vaccine development and clinical identification would not be possible without the ability to ________. A) culture viruses in vivo and in vitro B) transform human cells into cancerous cells C) studying prions in neurological tissue of animals D) activate lysogenic induction in bacteriophages

culture viruses in vivo and in vitro

A patient undergoing chemotherapy for cancer develops an infection with cytomegalovirus, conclusively diagnosed by the presence of "owl's eye" viral nuclear inclusions in a liver biopsy. This is an example of a(n) ________. A) cytopathic effect by cytomegalovirus B) immune response by the host C) cytomegalovirus becoming a provirus D) transformation of the host cell by cytomegalovirus

cytopathic effect by cytomegalovirus

Satellite viruses are ________. A) also called viroids B) dependent on other viruses for replication C) the cause of spongiform encephalopathies D) significant pathogens of plants E) All of the choices are correct

dependent on other viruses for replication

An ideal antiviral drug would be one that ________. A) disrupted an integral viral process while causing little damage to the host cell B) killed the host cell thereby depriving the virus of its means to translate proteins C) killed both the virus and the host cell D) prevents translation by the host cell ribosome, depriving the virus of a means to replicate

disrupted an integral viral process while causing little damage to the host cell

The core of every virus particle always contains ________. A) DNA B) capsomeres C) enzymes D) DNA and RNA E) either DNA or RNA

either DNA or RNA

During lysogeny, an inactive prophage state occurs when the viral DNA is inserted into the ________. A) host cytoplasm B) host nucleus C) host nucleolus D) host DNA E) host cell membrane

host DNA

Viruses attach to their hosts via ________. A) host glycoproteins B) host phospholipids C) viral phospholipids D) viral flagella E) All of the choices are correct

host glycoproteins

One of the principal capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a(n) ________ capsid. A) spiked B) complex C) icosahedral D) helical E) buckeyball

icosahedral

The activation of a prophage is called ________. A) activation B) lysogeny C) transformation D) induction E) adsorption

induction

T-even phages ________. A) include the poxviruses B) infect Escherichia coli cells C) enter host cells by engulfment D) have helical capsids E) All of the choices are correct

infect Escherichia coli cells

The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is ________. A) adsorption to the host cells B) injection of only the viral nucleic acid into the host cell C) host cell synthesis of viral enzymes and capsid proteins D) assembly of nucleocapsids E) replication of viral nucleic acid

injection of only the viral nucleic acid into the host cell

The envelope of enveloped viruses ________. A) is identical to the host plasma membrane B) is only composed of host endomembrane C) does not contain spikes D) is obtained by viral budding or exocytosis E) None of the choices are correct

is obtained by viral budding or exocytosis

Respiratory syncytial virus (RSV) is a common respiratory virus that causes mild cold-like symptoms in most individuals, but can be more serious in infants and the elderly. RSV is so-named because ________. A) it causes the fusion of damaged host cells, forming a large, multinucleated cell B) it causes the proliferation of inclusion bodies within the host cell C) it causes a persistent infection in the host D) it transforms the host cell, causing cancer

it causes the fusion of damaged host cells, forming a large, multinucleated cell

Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called ________. A) latent B) oncogenic C) prions D) viroids E) delta agents

latent

New, nonenveloped virus release occurs by ________. A) lysis B) budding C) exocytosis D) both lysis and budding E) both budding and exocytosis

lysis

When a bacterium acquires a trait from its temperate phage, it is called ________. A) transformation B) lysogenic conversion C) viral persistence D) transcription E) translation

lysogenic conversion

Oncoviruses include all the following except ________. A) hepatitis B virus B) measles virus C) papillomavirus D) HTLV I E) Epstein-Barr virus

measles virus

Viruses have all the following except ________. A) definite shape B) metabolism C) genes D) the ability to infect host cells E) ultramicroscopic size

metabolism

Cells grown in culture form a(n) ________. A) monolayer B) bilayer C) aggregate D) plaque E) None of the choices are correct.

monolayer

A negative-sense RNA virus ________. A) is ready for immediate translation B) must synthesize a negative RNA copy of its genome C) must synthesize a positive RNA copy of its genome D) is a special form of tRNA used by viruses E) always codes for RNA polymerase

must synthesize a positive RNA copy of its genome

A naked virus has only a(n) ________. A) capsid B) capsomere C) nucleocapsid D) envelope E) antigenic surface

nucleocapsid

In general, most DNA viruses multiply in the host cell's ________, while most RNA viruses multiply in the host cell's ________. A) nucleus; cytoplasm B) cytoplasm; cell membrane C) cell membrane; cytoplasm D) cytoplasm; nucleus E) nucleus; endoplasmic reticulum

nucleus; cytoplasm

Mammalian viruses capable of starting tumors are ________. A) chronic latent viruses B) oncoviruses C) syncytia D) inclusion bodies E) cytopathic

oncoviruses

Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called ________. A) lysogeny B) budding C) plaques D) cytopathic effects E) pocks

plaques

Viruses with ________ -sense RNA contain the correct message for translation, while viruses with ________ -sense RNA must first be converted into a correct message. A) positive; negative B) negative; positive C) primary; secondary D) secondary; primary E) None of the choices are correct

positive; negative

Infectious protein particles are called ________. A) viroids B) phages C) prions D) oncogenic viruses E) spikes

prions

Two noncellular agents, smaller than viruses, are the infectious proteins called ________ and the infectious RNA strands called ________. A) prions; capsomeres B) virions; prions C) viroids; phages D) prions; phages E) prions; viroids

prions; viroids

Viral spikes ________. A) are present on all viruses B) protrude from the envelope C) block attachment between virus and host D) are derived from host proteins E) All of the choices are correct

protrude from the envelope

Viruses acquire envelopes around their nucleocapsids during ________. A) replication B) assembly C) adsorption D) release E) penetration

release

What structures are used by bacteriophages to attach to host cell receptors? A) Sheath B) Tail fibers C) Nucleic acid D) Capsid head E) None of the choices are correct

tail fibers

You are running an experiment in calf serum, which cannot be autoclaved because proteins essential to your protocol will be denatured. You decide to filter sterilize the serum since the 0.22μm filter is small enough to block any bacteria that may contaminate your tissue culture. The success of this procedure hinges on the fact that ________. A) the presence of viruses in your serum is inconsequential to your experiment B) some of the bacteria will still be allowed to filter through C) viruses, as well as bacteria, will also be blocked by the 0.22μm pore size D) the proteins in the serum are also blocked by the pore size

the presence of viruses in your serum is inconsequential to your experiment

Viral tissue specificities are called ________. A) ranges B) virions C) receptacles D) tropisms E) uncoating

tropisms

Host range is limited by ________. A) type of nucleic acid in the virus B) age of the host cell C) type of host cell receptors on cell membrane D) size of the host cell E) All of the choices are correct

type of host cell receptors on cell membrane

The process of dissolving the envelope and capsid to release the viral nucleic acid is ________. A) adsorption B) penetration C) uncoating D) synthesis E) assembly

uncoating

Lysogeny refers to ________. A) altering the host range of a virus B) latent state of herpes infections C) virion exiting host cell D) viral genome inserting into bacterial host chromosome E) None of the choices are correct

viral genome inserting into bacterial host chromosome

Infectious naked strands of RNA that affect plants are called ________. A) viroids B) phages C) prions D) oncogenic viruses E) spikes

viroids

The development of antiviral drug therapy is difficult because ________. A) viruses are obligate intracellular parasites so the host cell can be harmed by the drug B) viruses do not have specific replication cycles that can be targeted C) viruses do not contain genetic material D) their life cycles do not have distinctive stages

viruses are obligate intracellular parasites so the host cell can be harmed by the drug

Which of the following occurs during assembly of an enveloped virus? A) Nucleocapsid is formed. B) New viral nucleic acid is formed. C) Viral spikes insert in host cell membrane. D) A nucleocapsid is formed and viral spikes insert in host cell membrane. E) All of the choices occur.

A nucleocapsid is formed and viral spikes insert in host cell membrane.

Creutzfeldt-Jakob disease is ________. A) caused by a chronic latent virus B) initiated by an oncogenic virus C) caused by a viroid D) a spongiform encephalopathy of humans E) also called "mad cow disease"

a spongiform encephalopathy of humans