Microbiology 020 - General Microbiology » Fall 2021 » Viruses 1

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Question #1
Every virus particle contains ________.
A.   DNA
B.   DNA and RNA
C.   either DNA or RNA
D.   ribosomes
Question #2
Viral capsids are composed of ________.
A.   protein
B.   carbohydrates
C.   lipids
D.   nucleic acids
Question #3
When present, what is the viral envelope composed of?
A.   Peptidoglycan
B.   Nucleic acid
C.   Proteins and lipids
D.   Carbohydrates
Question #4
Almost immediately upon entry, the viral nucleic acid alters the genetic expression of the host cell.
A.   FALSE
B.   TRUE
Question #5
Viral spikes ________.
A.   attach specifically to host cell receptors
B.   are present in all viruses
C.   are made of lipids
D.   attach nonspecifically to host cell receptors
Question #6
In viral entry by endocytosis ________.
A.   the host cell's plasma membrane surrounds the whole virion and forms a vesicle
B.   the host cell's plasma membrane surrounds only the viral nucleic acid coat and forms a vesicle
C.   the host cell's plasma membrane surrounds only the viral protein acid coat and forms a vesicle
D.   viral spikes fuse with the host cell's plasma membrane to form a vesicle
Question #7
Both enveloped and naked viruses can enter a cell by endocytosis.
A.   FALSE
B.   TRUE
Question #8
A naked virus fuses with the host cell membrane.
A.   FALSE
B.   TRUE
Question #9
What will happen once a virus has entered a host cell and uncoated?
A.   A new envelope will surround the nucleic acid
B.   The synthesis of new virions will occur
C.   The genetic material of the virus will disintegrate
D.   The virus will kill the cell
Question #10
Viruses can be grown on culture media like bacteria.
A.   FALSE
B.   TRUE
Question #11
Animal viruses always kill cells they infect.
A.   TRUE
B.   FALSE
Question #12
An envelope is acquired during which step of the viral life cycle?
A.   Synthesis
B.   Adsorption
C.   Penetration
D.   Release
Question #13
All viruses leave a cell by exocytosis.
A.   TRUE
B.   FALSE
Question #14
The capsid of a virus is ________.
A.   a protein shell that surrounds the nucleic acid
B.   made up mainly of polysaccharides
C.   a phospholipid bilayer that surrounds the nucleic acid
D.   a subunit of the viral cell wall
Question #15
The general steps in viral replication (in order) are ________.
A.   adsorption, penetration, synthesis, release, assembly
B.   adsorption, penetration, release, synthesis, assembly
C.   adsorption, penetration, synthesis, assembly, release
D.   penetration, synthesis, assembly, release
Question #16
The T-even bacteriophages such as T2 and T4 infect ________.
A.   Escherichia coli
B.   tobacco leaves
C.   Staphylococcus aureus
D.   Clostridium tetani
Question #17
A major difference in the replication of animal viruses and bacteriophages is the ______ step.
A.   assembly
B.   penetration
C.   release
D.   synthesis
Question #18
A bacteriophage initially associates with which bacterial structure?
A.   Bacterial ribosomes
B.   The cytoplasmic membrane
C.   The bacterial cell wall
D.   The bacterial chromosome
Question #19
Bacteriophage DNA directs the degradation of the bacterial host cell's DNA.
A.   TRUE
B.   FALSE
Question #20
Once inside the host cell, viral DNA directs production of _______.
A.   bacterial exotoxins
B.   bacterial endospores
C.   new viral particles
D.   bacterial flagella
Question #21
The final step in T2 bacteriophage infection results in _______.
A.   incorporation of viral DNA into the bacterial chromosome
B.   rapid reproduction of new bacterial cells
C.   lysis of the bacterial cell and release of new viral particles
D.   mutation of bacterial DNA
Question #22
Phage DNA encodes for the proteins of the viral capsid and ________.
A.   lipases that allow the virus to escape the cell
B.   transmembrane proteins that allow the virus to escape the cell
C.   regulatory proteins which direct the production and assembly of the capsid proteins
D.   spike proteins that are inserted into the plasma membrane
Question #23
How does bacteriophage DNA get into the host cell?
A.   It is injected
B.   It attaches to receptors which bring in a single-strand
C.   By fusion with the cell's plasma membrane
D.   By receptor-mediated endocytosis
Question #24
Viral cycles that end in release of the new phages and immediate destruction of the host bacterial cell are referred to as ______.
A.   acute
B.   lysogenic
C.   lytic
D.   latent
Question #25
T-even phages can replicate independently of a host cell.
A.   TRUE
B.   FALSE
Question #26
The first event to occur is _______.
A.   the viral capsid becomes enclosed by the cell membrane
B.   viral spike proteins are inserted into the host cell membrane
C.   the inside of the host cell membrane becomes coated with viral matrix protein
D.   the inside of the host cell membrane becomes coated with capsid
Question #27
The viral capsid _______.
A.   is dissolved
B.   becomes completely enclosed by the region of the cell membrane into which the spikes and matrix protein are embedded
C.   engulfs the viral spikes
D.   surrounds the viral matrix protein
Question #28
Enveloped viruses are usually released from the host cell by _______.
A.   phagocytosis
B.   budding
C.   endocytosis
D.   lysis of the host cell
Question #29
A portion of the viral envelope comes from the cell membrane of the host cell.
A.   TRUE
B.   FALSE
Question #30
Enveloped viruses are usually released from the host cell by exocytosis.
A.   FALSE
B.   TRUE
Question #31
In the lytic cycle of phage replication, _______.
A.   phage genes exist as prophage
B.   phage nucleic acid is replicated and phage genes are expressed, making new phage protein and lysing the host cell
C.   phage DNA remains inside the protein coat
D.   phage genes integrate into the host cell genome and are not expressed
Question #32
A prophage is ________.
A.   phage protein left outside the bacterium
B.   phage DNA integrated into host cell genome
C.   toxic to the host bacterial cell
D.   phage DNA being actively expressed
Question #33
Which of the following can cause a phage in the lysogenic stage to revert to the lytic stage?
A.   Darkness
B.   Ultraviolet light
C.   Lack of nutrients
D.   An electrical charge
E.   A competing phage
Question #34
In the lysogenic stage of phage replication, the host cell is lysed.
A.   FALSE
B.   TRUE
Question #35
Once a phage becomes lysogenic, it will remain lysogenic and never be lytic again.
A.   TRUE
B.   FALSE

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