Microbiology Chapter 7 Viruses & Prions || with Accurate
Answers.
Properties of Viruses correct answers Obligate intracellular parasites, not capable of living
independently, acellular
Structure of Viruses correct answers All have 1 nucleic acid and a capsid. Can have an
envelope.
Nucleic Acid correct answers DNA or RNA. May be single or double stranded
Capsid correct answers Coat or protein surrounding the nucleic acid. Composed of individual
subunits called capsomeres. Variety of shapes.
Common Animal Virus Capsid Shapes correct answers Helical and icosahedral
Icosahedral correct answers 20 sided figure
Common Bacteria Virus Capsid Shapes correct answers complex
Envelope correct answers Outer bilayer membrane surrounding capsid in some viruses, a
piece of the host's plasma membrane.
naked virus correct answers virus without an envelope
virion correct answers A fully formed virus particle including nucleic acid, capsid, and
envelope. May contain enzymes for viral replication.
All cells are susceptible to being infected by some type of virus. Every virus has particular
organisms and cell types that it can infect. correct answers What hosts and cells can viruses
infect?
Host range correct answers Spectrum of hosts a virus can infect. Ex: Polio infects only
humans while rabies infects warm-blooded animals.
viral specificity correct answers Specific types of cells within a host that a virus can infect.
Ex: Papillomavirus infects skin cells.
Type of organisms it can infect, type of nucleic acid, capsid morphology, envelope, size, and
host range & viral specificity. correct answers What criteria are used to identify viruses?
Virion structure, chemical composition, and genetic homology correct answers What criteria
are most commonly used to classify viruses?
Naming viruses correct answers Binomial names, species name is the common English name
like rabies.
Viral Replication correct answers Viruses use host cell machinery to make and assemble new
virus particles
, adsoprtion correct answers Virus binds to target host cell
Penetration correct answers Virus enters the host cell. Animal cells can enter through
membrane fusion or receptor-mediated endocytosis.
Membrane fusion correct answers Capsid and nuclei acid enter the cytoplasm
receptor-mediated endocytosis correct answers Envelope, capsid, and nucleic acid enter
cytoplasm
Uncoating correct answers Capsid and envelope are removed to release nucleic acid
Biosynthesis correct answers Nucleic acid is copied and viral proteins are synthesized
Maturation correct answers Viral proteins are assemble to form capsid. viral nucleic acid is
inserted into the capsid. viral proteins are inserted into the host cell's membrane.
Budding release correct answers exocytosis; nucleocapsid binds to membrane which pinches
off and sheds the viruses gradually; cell is not immediately destroyed
Lysis of the host cell release correct answers Host cell ruptures and the virus particles are
released
8-36 hours correct answers How long do animal viruses replicate for?
Retroviruses correct answers contain single-stranded RNA genome, to which a
complementary DNA strand is made using reverse transcriptase. The DNA strand can then be
integrated into the genome as a provirus.
Provirus dormancy correct answers Viruses can remain dormant or become activated at any
time.
provirus activation correct answers When genes are activated, new viral mRNA is
synthesized, viral proteins are made and new virus particles are synthesized.
cytopathic effect (CPE) correct answers virally induced changes to the cell cultures
-changes in cell shape, detachment of cells, fluid accumulation(swelling), lysis, fusion of
cells, transformation into malignant cells, cytoplasmic inclusion(various molecules).
Latent infections correct answers Viruses evaded immune systems by hiding in other cells.
Present in host without symptoms. Reactivated by various stimuli. Ex. Chicken pox and
shingles
Cancer correct answers Uncontrolled, invasive growth of abnormal cells
oncogenic viruses correct answers viruses that can cause cancer
Human oncogenic viruses correct answers HPV and cervical cancer. Epstein-Barr virus and
nasopharynx cancer. Hepatitis B and liver cancer. HTLV-I and 1 type of leukemia
Answers.
Properties of Viruses correct answers Obligate intracellular parasites, not capable of living
independently, acellular
Structure of Viruses correct answers All have 1 nucleic acid and a capsid. Can have an
envelope.
Nucleic Acid correct answers DNA or RNA. May be single or double stranded
Capsid correct answers Coat or protein surrounding the nucleic acid. Composed of individual
subunits called capsomeres. Variety of shapes.
Common Animal Virus Capsid Shapes correct answers Helical and icosahedral
Icosahedral correct answers 20 sided figure
Common Bacteria Virus Capsid Shapes correct answers complex
Envelope correct answers Outer bilayer membrane surrounding capsid in some viruses, a
piece of the host's plasma membrane.
naked virus correct answers virus without an envelope
virion correct answers A fully formed virus particle including nucleic acid, capsid, and
envelope. May contain enzymes for viral replication.
All cells are susceptible to being infected by some type of virus. Every virus has particular
organisms and cell types that it can infect. correct answers What hosts and cells can viruses
infect?
Host range correct answers Spectrum of hosts a virus can infect. Ex: Polio infects only
humans while rabies infects warm-blooded animals.
viral specificity correct answers Specific types of cells within a host that a virus can infect.
Ex: Papillomavirus infects skin cells.
Type of organisms it can infect, type of nucleic acid, capsid morphology, envelope, size, and
host range & viral specificity. correct answers What criteria are used to identify viruses?
Virion structure, chemical composition, and genetic homology correct answers What criteria
are most commonly used to classify viruses?
Naming viruses correct answers Binomial names, species name is the common English name
like rabies.
Viral Replication correct answers Viruses use host cell machinery to make and assemble new
virus particles
, adsoprtion correct answers Virus binds to target host cell
Penetration correct answers Virus enters the host cell. Animal cells can enter through
membrane fusion or receptor-mediated endocytosis.
Membrane fusion correct answers Capsid and nuclei acid enter the cytoplasm
receptor-mediated endocytosis correct answers Envelope, capsid, and nucleic acid enter
cytoplasm
Uncoating correct answers Capsid and envelope are removed to release nucleic acid
Biosynthesis correct answers Nucleic acid is copied and viral proteins are synthesized
Maturation correct answers Viral proteins are assemble to form capsid. viral nucleic acid is
inserted into the capsid. viral proteins are inserted into the host cell's membrane.
Budding release correct answers exocytosis; nucleocapsid binds to membrane which pinches
off and sheds the viruses gradually; cell is not immediately destroyed
Lysis of the host cell release correct answers Host cell ruptures and the virus particles are
released
8-36 hours correct answers How long do animal viruses replicate for?
Retroviruses correct answers contain single-stranded RNA genome, to which a
complementary DNA strand is made using reverse transcriptase. The DNA strand can then be
integrated into the genome as a provirus.
Provirus dormancy correct answers Viruses can remain dormant or become activated at any
time.
provirus activation correct answers When genes are activated, new viral mRNA is
synthesized, viral proteins are made and new virus particles are synthesized.
cytopathic effect (CPE) correct answers virally induced changes to the cell cultures
-changes in cell shape, detachment of cells, fluid accumulation(swelling), lysis, fusion of
cells, transformation into malignant cells, cytoplasmic inclusion(various molecules).
Latent infections correct answers Viruses evaded immune systems by hiding in other cells.
Present in host without symptoms. Reactivated by various stimuli. Ex. Chicken pox and
shingles
Cancer correct answers Uncontrolled, invasive growth of abnormal cells
oncogenic viruses correct answers viruses that can cause cancer
Human oncogenic viruses correct answers HPV and cervical cancer. Epstein-Barr virus and
nasopharynx cancer. Hepatitis B and liver cancer. HTLV-I and 1 type of leukemia
