PreTest Chapter 13 - Viruses, Viroids, and Prions

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

B) metabolism

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.

E) All of the choices are correct.

Viruses ______.

A) cannot be seen in a light microscope
B) are prokaryotic
C) contain 70S ribosomes
D) undergo binary fission

A) cannot be seen in a light microscope

Viral capsids are made from subunits called ______.
A) envelopes
B) spikes
C) capsomeres
D) prophages
E) peptones

C) capsomeres

Helical and icosahedral are terms used to describe the shape of a viral ______.
A) spike
B) capsomere
C) envelope
D) capsid
E) core

D) capsid

A/an _______ is the protein shell around the nucleic acid core of a virus.
A) capsomere
B) capsid
C) spike
D) envelope
E) monolayer

B) capsid

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

C) icosahedral

A naked virus only has a/an ______.
A) capsomere
B) nucleocapsid
C) envelope
D) antigenic surface

B) nucleocapsid

Which of the following is not a typical capsid shape?

A) Tetrahedral
B) Complex
C) Helical
D) Icosahedron

A) Tetrahedral

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

E) located between the capsid and nucleic acid

Viral spikes ________.
A) are always present on enveloped viruses
B) attach the viral capsid and envelope
C) allow bacteria to evade host defenses
D) are derived from host proteins
E) are for recognition among the various types of viruses

A) are always present on enveloped viruses

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

E) either DNA or RNA

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

A) Envelope

Viral nucleic acid types 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.

E) All of the choices are correct.

Reverse transcriptase synthesizes ________.
A) a positive RNA strand from a negative RNA strand
B) a negative RNA strand from a positive RNA strand
C) viral RNA from DNA
D) viral DNA from RNA

D) viral DNA from RNA

A negative RNA virus must first ________.
A) synthesize a DNA copy of its genome
B) synthesize a negative RNA copy of its genome
C) synthesize a positive RNA copy of its genome
D) transcribe reverse transcriptase
E) transcribe RNA polymerase

C) synthesize a positive RNA copy of its genome

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) intermediate; primary

A) positive;negative

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) number of strands in the nucleic acid

D) 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

B) Herpesviridae

Which of the following is not a viral order in the classification system?
A) Caudovirales
B) Vaccinia virus
C) Nidovirales
D) Mononegavirales

B) Vaccinia virus

) The correct sequence of events in viral multiplication is ________.

A) penetration, uncoating, synthesis, adsorption, assembly, and release
B) uncoating, penetration, synthesis, assembly, absorption, and release
C) adsorption, penetration, uncoating, synthesis, assembly, and release
D) assembly, synthesis, uncoating, release, penetration, and adsorption
E) adsorption, release, synthesis, uncoating, assembly, and penetration

C) adsorption, penetration, uncoating, synthesis, assembly, and release

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

D) release

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; cellmembrane
C) cell membrane;cytoplasm
D) cytoplasm;nucleus
E) nucleus;endoplasmic reticulum

A) nucleus;cytoplasm

Host range is limited by the _______.
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

C) type of host cell receptors on cell membrane

Oncogenic viruses include all the following except ______.
A) hepatitis B virus
B) measles virus
C) Papillomavirus
D) HTLV-I and HTLV-II viruses
E) Epstein-Barr virus

B) measles virus

Which of the following is/are type(s) of cytopathic effects?
A) Inclusions in the nucleus
B) Multinucleated giant cells
C) Inclusions in the cytoplasm
D) Rounding of cells
E) All of the choices are correct.

E) All of the choices are correct.

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) makes the virus very susceptible to drug therapy

D) is obtained by viral budding or exocytosis

Viruses attach to their hosts via ______.
A) host glycoproteins
B) host phospholipids
C) viral phospholipids
D) viral flagella
E) carbohydrate attachments of the viral capsid

A) host glycoproteins

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

D) tropisms

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

C) uncoating

Which of the following occurs during assembly?
A) The nucleocapsid is formed.
B) New viral nucleic acid is formed.
C) Viral spikes insert in host cell membrane.
D) The nucleocapsid is formed and viral spikes insert in host cell membrane.
E) The viral envelope and the host cell membrane fuse.

D) The nucleocapsid is formed and viral spikes insert in host cell membrane.

Mammalian viruses capable of starting tumors are ______.

A) chronic latent viruses
B) oncoviruses
C) syncytia
D) inclusion bodies

B) oncoviruses

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

A) chronic latent viruses

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

B) Decreased growth rate

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

A) lysis

What structures are used by bacteriophages to attach to host cell receptors?
A) Viral sheaths
B) Tail fibers
C) Nucleic acids
D) Capsid heads

B) Tail fibers

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

D) Cause lysis of host cells

T-even phages ______.
A) include the poxviruses
B) infect Escherichia coli cells
C) enter host cells by engulfment
D) have helical capsids

B) infect Escherichia coli cells

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

A) latent

In transduction, the viral genome _______.
A) initiates lysis of the host
B) includes DNA from the previous host
C) is replicated in the cytoplasm
D) is replicated in the nucleus

B) includes DNA from the previous host

Lysogeny refers to _______.
A) altering the host range of a virus
B) the latent state of herpes infections
C) virions exiting host cell
D) the viral genome inserting into bacterial host chromosome

D) the viral genome inserting into bacterial host chromosome

Viruses that infect bacteria are specifically called ______.
A) viroids
B) prions
C) bacteriophages
D) satellite viruses

C) bacteriophages

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

D) DNA

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

C) Temperate

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

D) induction

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

B) lysogenic conversion

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.

E) All of the choices will support viral cultivation.

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

C) plaques

Viral growth in bird embryos can cause discrete, opaque spots in the embryonic membranes called ______.
A) patches
B) buds
C) plaques
D) cytopathic effects
E) pocks

E) pocks

Cells grown in culture form a/an ______.
A) monolayer
B) bilayer
C) aggregate
D) plaque

A) monolayer

Diagnosis of viral infections sometimes involves analyzing the patient's blood for specific _____ that the immune system produces against the virus.
A) glycoproteins
B) antibodies
C) complementproteins
D) antigens

B) antibodies

Freshly isolated animal tissue that is placed in a growth medium and allowed to produce a cell monolayer is referred to as a/n _____ cell culture.
A) initial
B) primary
C) secondary
D) continuous
E) positive

B) primary

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

B) cell

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

C) prions

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

A) viroid

Creutzfeldt-Jacob 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"

D) a spongiform encephalopathy of humans

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

B) dependent on other viruses for replication

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

E) prions;viroids

Who developed a rabies vaccine after realizing the disease was caused by something smaller than a bacterium?
A) Leeuwenhoek
B) Koch
C) Pasteur
D) Cohn
E) Ivanovski

C) Pasteur

How are viroids transmitted?
A) Respiratory secretions
B) Sex
C) Plant seeds
D) Blood products

C) Plant seeds

Successful anti-HIV drug therapies today work by blocking the action of viral reverse transcriptase. Select which step of virus multiplication that would be directly blocked by this mechanism.
A) Adsorption
B) Penetration
C) Synthesis
D) Assembly
E) Release

C) Synthesis