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59 terms

CH13Quiz

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They require a host in order to reproduce.
How are viruses different from cells?
Package and protect the viral genome
Function of a viral structural elements.
Their nucleic acids are injected into the cell
How do naked viruses differ from enveloped viruses in their attachment/penetration phase?
Retrovirus
Which of the following viruses is transcribed from RNA to DNA to RNA during the replication cycle?
Enveloped viruses
Which type of virus would produce viral glycoproteins to be expressed on the host cell membrane?
Lysogeny
Lysogenic viral DNA integrating into the host genome is referred to as
what?
Exposure to UV light
Which of the following events might trigger induction of a temperate bacteriophage?
The host cell dies during the lytic stage
How is the lytic cycle different from the lysogenic cycle with respect to the infected host cell?
It is copied every time the host DNA replicates.
What is the fate of the prophage during the lysogenic stage?
Prophage
In which stage is the viral DNA introduced into the cell?
Assembly
In which stage does formation of mature viruses occur?
Synthesis
The host DNA is usually degraged during which stage?
The virus would not be able to infect new hosts.
What would be the fate of a lytic bacteriophage if the host cell died prior to the assembly stage?
Capsomere, Capsid, Nucleocapsid, Virion
The following viral structures are in order from simplest to most complex.
Most viruses can infect only certain types of cells.
Most viral genomes are much smaller than the genomes of the cells they infect. Which of the following CANNOT be inferred from this statement?
It does not perform the physiological functions carried out by the cytoplasmic membrane
The envelope found in some virus particles differs from the cytoplasmic membrane of cells in what way?
Nucleocapsid
The combination of a virus's protein coat and nucleic acid core
Viral capsids
What can assume one of three basic shapes?
Envelope
Some viruses have an outer membrane
Tobacco virus
What is the first virus to be discovered and characterized?
Capsomeres
Subunits that compose viral capsids
Icosahedron
20-sided polyhedral capsid
Nucleic acid, presence of envelope, shape, size
How viruses are classified
Interactions between viral and cellular surface molecules
Host specificity of a virus is due to what?
Naked virion
Animal virus that does not have an envelope
Cells and viruses
Lipid membrane present in which type of organism?
In both cells and viruses
Double-stranded DNA genomes are found in which type of organism?
Only in viruses
Double-stranded RNA genomes can be found in which type of organism?
Cells only
Cytoplasm is a characteristic of which type of organism?
Proteins
These are found in both cells and viruses.
Infected cell may live for a long time
Infections with enveloped animal viruses are similar to lysogenic phage infections because
Attachment
A phage T4 particle that has lost its tail fibers will have a replication cycle that is blocked at which of the following stages?
Temperate phage
Another term for a lysogenic phage
Uncoating
A process in which viral capsids are removed within the infected cell.
Random collisions, chemical attractions, and receptor specificity
Which of the following is associated with the attachment of a bacteriophage to a bacterial cell?
Assembly
The phenomenon of transduction is associated with which of the stages of a bacteriophage infection cycle?
The genetic material of the bacteriophage can be passed on to future generations of cells
Why is lysogeny advantageous to a bacteriophage?
The nuclear and cytoplasmic membranes and the endoplasmic reticulum
Which of the following membranes can give rise to a viral envelope?
The HIV provirus is integrated permanently into the host cell's DNA
How is the HIV provirus different from a lambda phage prophage?
Latency
During ______, viruses remain dormant in a cell.
Lytic
Virus replication results in the death of the cell in a(n) infection.
Budding
A mechanism of release for enveloped viruses
Virion
Which of the following terms refers to a virus in the extracellular state?
Plant
The first virus to be identified was isolated from what type of organim?
Protein
The capsid of a virus is made out of which of the following types of molecules?
Helical, polyhedral, complex
Basic types of viral shapes
They are dependent on host cell organelles and enzymes for their replication.
Why do viruses have to infect host cells?
Tail Fibers
The ____ of a bacteriophage are most useful the attachment stage of the lytic replication cycle.
Viral DNA becomes a physical part of the bacterial chromosome only in a lysogenic cycle.
Which of the following is a major difference between a lysogenic and a lytic cycle in bacteriophages?
Pili, flagella, cell wall
Bacteriophages can use all of the following structures for attachment to a bacterial cell
The phage persists for generations in the bacterial chromosome.
What is the advantage of lysogeny to lambda phage
Continuous
HeLa cells are an example of a _____ cell culture.
contain no nucleic acid
Scientists have determined that prion diseases are not caused by a type of slow virus because prions
Spontaneous process
The assembly stage of the viral life cycle is usually a ______, although in some viruses it is controlled by enzymes
Induction
A prophage is excised from the host chromosome and viral replication proceeds in a process called _____.
Viroids
Small, circular RNA molecules that are infectious to plants are called___
Persistent
An infection in which a host cell sheds new viruses slowly and steadily is called a(n) __________ infection.
Plaque
A technique used to estimate the numbers of bacteriophages in a culture is called a(n) __________ assay.
Spongiform Encephalopathies
As a group, prion diseases are more formally known as ______.