micro quiz 5
Host range is limited by the
. type of host cell receptors on cell membrane.
During lysogeny, an inactive prophage state occurs when the viral DNA is inserted into the host ___
DNA
Which of the following will not support viral cultivation?
Live lab animals b. Primary cell cultures c. Continuous cell cultures d. Embryonated bird eggs all of the above
Which of the following is/are type(s) of cytopathic effects?
Multinucleated giant cells b. Rounding of cells c. Inclusions in the nucleus d. Inclusions in the cytoplasm all are correct
Which of the following occurs during assembly?
The nucleocapsid is formed and viral spikes insert in host cell membrane
The correct sequence of events in viral multiplication is
adsorption, penetration, uncoating, synthesis, assembly, and release. Correct
Diagnosis of viral infections sometimes involves analyzing the patient's blood for specific _____ that the immune system produces against the virus.
antibodies
Viruses that infect bacteria are specifically called
bacteriophages
Viral capsids are made from subunits called ______.
capsomeres
A common method for cultivating viruses in the lab is to use in vitro systems called _____ cultures.
cell
Persistent viruses that can reactivate periodically are ___
chronic latent viruses
Viruses attach to their hosts via ______.
host glycoproteins
In transduction, the viral genome
includes DNA from the previous host
The activation of a prophage is called __
induction
T- even phages
infect Escherichia coli cells
The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is
injection of only the viral nucleic acid into the host cell
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 ______
measles virus
A naked virus only has a/an
nucleocapsid
In general, most DNA viruses multiply in the host cell's _____, while most RNA viruses multiply in the host cell's
nucleus: cytoplasm
uncoating of viral nucleic acid
occurs during penetration in the multiplication cycle. b. does not occur in bacteriophage multiplication. c. involves enzymatic destruction of the capsid. d. occurs before replication. all of the above
Mammalian viruses capable of starting tumors are ______.
oncoviruses
Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called ______.
plaques
Two noncellular agents, smaller than viruses, are infectious proteins called _____ and infectious RNA strands called _____.
prions: viroids
Viruses acquire envelopes around their nucleocapsids during ______.
release
What structures are used by bacteriophages to attach to host cell receptors?
tail fibers
What type of phage enters an inactive prophage stage?
temperate
Lysogeny refers to
the viral genome inserting into bacterial host chromosome
Which of the following represents a virus family name?
a. Hepatitis B virus b. Herpesviridae Correct c. Picornavirus d. Enterovirus e. Herpes simplex virus herpesviridae
Viruses exhibit all the following except ______
a. ultramicroscopic size b. definite shape c. metabolism Correct d. genes e. ability to infect host cells metabolism