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62 terms

Microbiology Talaro 8th ed. Ch 6

Micro test2 chap6
STUDY
PLAY
Viruses have all the following except
A. definite shape.
B. metabolism.
C. genes.
D. ability to infect host cells.
E. ultramicroscopic size.
Metabolism
Host cells of viruses include
A. human and other animals.
B. plants and fungi.
C. bacteria.
D. protozoa and algae.
E. All of the choices are correct.
All are correct
The core of every virus particle always contains
either DNA or RNA.
Classification of viruses into families involves determining all the following characteristics except
A. type of nucleic acid.
B. type of capsid.
C. presence of an envelope.
D. biochemical reactions.
E. nucleic acid strand number.
Biochemical Reactions
Which of the following represents a virus family name?
A. Herpes simplex virus
B. Herpesviridae
C. Picornavirus
D. Enterovirus
E. Hepatitis B virus
Herpesviridae
Virus capsids are made from subunits called
capsomeras
Helical and icosahedral are terms used to describe the shapes of a virus
Capsid
Which of the following is correct about viruses?
A. cannot be seen with a light microscope
B. are procaryotic
C. contain 70S ribosomes
D. undergo binary fission
E. can be grown on nutrient agar
Cannot be seen with a light microscopr
All of the following pertain to virus envelopes except they
A. are gained as a virus leaves the host cell membrane.
B. are gained as a virus leaves the nuclear membrane.
C. contain special virus proteins.
D. help the virus particle attach to host cells.
E. are located between the capsid and nucleic acid.
Help the virus particles attach to host cells
Which of the following is not associated with every virus?
A. envelope
B. capsomers
C. capsid
D. nucleic acid
E. genome
Envelope`
These 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.
None are correct
Which 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
T-even phages
Infect Escherichia Coli cells
The correct sequence of events in viral multiplication is
Adsorption, penetration, replication, maturation, assembly, release.
The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is
Injection of the viral nucleic acid into the host cell.
Viruses acquire envelopes around their nucleocapsids during
Release
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. blood agar
Blood agar
In general, most DNA viruses multiply in the host cell's _____, while most RNA viruses multiply in the host cell's _____.
Nucleus, Cytoplasm
Host range is limited by
Type of host cell receptors on cell membrane
The virus-induced, specific damage to the host cell that can be seen in a light microscope is called
Cytopathic effects
Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called
Plaques
Viral growth in bird embryos can cause discrete, opaque spots in the embryonic membranes called
Pocks
Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called
Latent
Oncogenic viruses include all the following except
A. hepatitis B virus.
B. measles virus.
C. papillomavirus.
D. HTLVI and HTLVII viruses.
E. Epstein-Barr virus.
Measles virus
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 round up
E. All of the choices are correct.
All are correct
Uncoating of viral nucleic acid
Does not occur in bacteriophage multiplication.
Infectious protein particles are called
Prions
Infectious naked strands of RNA are called
Viroids
Creutzfeld-Jacob disease is
"Mad Cow" Disease
Satellite viruses are
Dependent on other viruses for replication.
All of the following is correct about treating viral diseases except
A. viruses are killed by the same antibiotics that kill bacteria.
B. many antiviral drugs block viral replication.
C. many antiviral drugs cause severe side effects.
D. interferons show potential for treating and preventing viral infections.
E. All of the choices are correct.
Viruses are killed by the same antibiotics that kill bacteria.
The capsomers are made of
Protein
Viruses that consist of only a nucleocapsid are considered
Naked Viruses
The nucleocapsid consists of
The nucleic acid along with the capsid.
Which of the following parts of a virus is not always present?
A. envelope
B. nucleic acid
C. capsid
D. capsomers
E. None of the choices are optional parts of a virus.
Envelope
Which of the following viruses did D. Ivanovski and M. Beijerinck work with?
A. rabies
B. smallpox
C. tobacco mosaic virus
D. herpes
E. Epstein-Barr virus
Tobacco Mosaic virus
Viruses belong to which of the following Kingdoms?
A. Protists
B. Fungi
C. Archaea
D. Bacteria
E. None of the choices are correct.
None are correct
Which body system is mainly affected by Creutzfeldt-Jakob disease?
Nervous
When a virus enters a lysogenic phase, it means
The virus is integrated into the DNA of the host cell and is latent.
All of the following are characteristics of viruses except
A. they can be crystallized.
B. they often have a geometric capsid.
C. they have a viscous fluid inside their capsids.
D. they can cause fatal diseases.
E. they can cause mild diseases.
They have a viscous fluid inside their capsids
How do enveloped animal viruses exit their host?
Budding or exocytosis
Clostridium botulinum is made virulent by incorporated prophage genes encoding for the botulinum toxin. What term describes this process?
Lysogenic conversion
Viruses are ultramicroscopic because they range in size from 2 mm to 450 mm.
True False
False
Spikes are glycoproteins of the virus capsid.

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

True False
False
Viral infections are easier to treat with drugs than bacterial infections.

True False
False
The International Committee on Taxonomy of Viruses has determined that there are only three orders of viruses.

True False
True
Bacteriophages do not undergo adsorption to specific host cell receptors prior to penetration.

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

True False
True
Viral spikes are inserted into the host cell membrane before budding or exocytosis occurs.

True False
True
No cases of variant Creutzfeldt-Jakob syndrome linked to eating infected cows have occurred in the United States.

True False
True
The adeno-associated virus (AAV) and the delta agent are prions.

True False
False
A _____ is the protein shell around the nucleic acid core of a virus.
Capsid
Viruses that infect bacteria are specifically called _____.
Bacteriophages
Diagnosis of viral infections sometimes involves analyzing the patient's blood for specific _____ that the immune system produced against the virus.
Antibodies
Two noncellular agents, smaller than viruses, are the infectious proteins called _____, and the infectious RNA strands called _____.
Prions, Virions
Viruses with _____ sense RNA contain the correct message for translation, while viruses with _____ sense RNA must first be converted into a correct message.
Positive, Negative
Freshly isolated animal tissue that is placed in a growth medium and allowed to produce a cell monolayer is referred to as a _____ cell culture.
In vitro
One of the principal capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as an _____ capsid.
Icosahedral
A naked virus does not have an _____.
envelope
During lysogeny, an inactive prophage state occurs when the viral DNA is inserted into the _____ _____.
Bacterial chromosome
A common method for cultivating viruses in the lab is to use in vitro systems called _____ cultures.
Cell/Tissue