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21 terms

Ch 13

A virion is
A. A complete, infectious virus particle.
B. A naked, infectious piece of RNA
C. A capsid without a nucleic acid
D. A provirus
E. None of the above.
The definition of lysogeny is
A. Phage DNA is incorporated into host cell's chromosome.
B. Lysis of the host cell due to a phage
C. The period during replication when virions are not present.
D. When the burst time takes a unusually long time.
A clearing due to phage replication on a confluent "lawn" of bacteria is called a
A. Pimple.
B. Pock.
C. Cell lysis.
D. Plaque.
E. None of the above.
Cytopathic effects are changes in host cells due to
A. viral infections.
B. fungal infections.
C. phage infections.
D. bacterial infections.
E. all of the above.
All viruses possess
A. a capsid and an envelope.
B. DNA as well as RNA.
C. a genome and a capsid.
D. only DNA.
E. only RNA.
A bacteriophage is a type of virus that
A. is destroyed by bacteria.
B. multiplies in bacteriological media.
C. coexists with bacteria during time of disease.
D. replicates within bacteria.
E. lives within the bacterial nucleus.
The togaviridae cause equine encephalitis and other diseases. These RNA viruses have a symmetrical capsid with 20 equilateral triangles and 20 edges and 12 points. Such a capsid is an example of a(n)
A. helical capsid
B. icosahedral capsid
C. complex capsid
D. ovoid capsid.
Describes a method by which an envelope virus leaves the host cell while acquiring an envelope.
A. Budding
B. Endocytosis.
C. Uncoating.
D. Adsorption
E. Penetration.
Latent animal viruses are present in cells as
A. Capsids.
B. Enzymes.
C. Proviruses
D. Prophages
E. None of the above.
The following steps occur during multiplications of the DNA virus like Herpes viruses. What is the third step?
A. Attachment
B. Biosynthesis
C. Penetration
D. Release
E. Uncoating
Viral envelopes are usually acquired by
A. budding through the membrane of the cell.
B. synthesizing envelope lipids under direction of the virus
C. an outgrowth of the genome membrane.
D. interaction between genes and oncogenes
The neuramindase of influenza viruses assists in
A. attachment to the host cells.
B. digestion of nuclear component of the cell
C. assembly of viral components.
D. release of virus through the cell membrane
E. disintegration of the cell at the end of the virus replication.
Animal viruses have attachment sites
A. only on the envelope of the virus.
B. over the entire surface of the capsid.
C. only on the nucleic acid portion of the virus.
D. on the tail of the virus.
E. within the genome of the virus.
The retrovirus can synthesize DNA from RNA because it contains
A. the necessary glucose molecules.
B. envelope proteins that provide receptor sites.
C. the enzyme reverse transcriptase.
D. cytoplasm within it genome
The viruses of influenza, measles and mumps are know for their ability to
A. multiply within bacteria
B. clump red blood cells.
C. form Negri bodies in brain cells
D. cause cancer
E. exist in horses.
16. The nucleic acid of a virus encased in its protein coat is often referred to as the
A. genome.
B. nucleocapsid.
C. virion.
D. capsid.
Yellow fever is a viral disease of the liver. As such, the yellow fever virus is classified as a
A. pneumotrophic virus
B. dermotropic virus
C. viscerotropic virus.
D. neurotropic virus.
You have isolated an animal virus whose capsid is a tightly wound coil resembling a corkscrew or spring. Such a capsid is referred to as a(n)
A. icosahedron.
B. helix
C. complex virion
D. capsomere
Rous sarcoma virus causes a cancer in chickens. This is a(n) ________ virus, which is classified in the _____________ because it contains reverse transcriptase.
A. DNA, papovaviridae
B. RNA, papovaviridae
C. DNA, retroviridae
D. RNA, retroviridae
The rabies virus is a(n) __________ virus, which is classified in the ________ group.
A. DNA, herpesvirieae
B. RNA, herpesviridae
C. DNA, rhabdoviridae
D. RNA, rhabdoviridae
All the following are possible methods for cultivating viruses except
A. fertilized chicken eggs.
B. tissue cultures.
C. laboratory animals.
D. blood agar medium.