Intro to virology

The outer surface of the capsid mediates with host cells.

The glycoproteins anchored in the envelope and pointing out mediate contact with the host cells.

Which type of virus is especially Sensitive to lipid solvents (ex. Chloroform, ether) and also to non-ionic detergents.

[blank_start]Naked[blank_end] viruses tend to be more stable to environmental changes than [blank_start]enveloped[blank_end] viruses.

[blank_start]Enveloped[blank_end] viruses are usually transmitted via aqueous environment: e.g. various body secretions, blood

[blank_start]Naked[blank_end] viruses may be transmitted by many routes: e.g. secretions/blood, oral-fecal, skin contact

What viral structure is defined as a lipid bilayer derived from host cell membranes during the process of virus maturation.

Which viral structure is defined as a protein shell that surrounds and protects the viral genome?

[blank_start]Icosahedral[blank_end] structures approximate spheres.

Icosahedral structures can have which of the following axis/axes of symmetry? (Select all that apply)

Helical structures can have which of the following axis/axes of symmetry? (Select all that apply)

The Corona family of viruses is classified as - [blank_start]Enveloped[blank_end] -[blank_start]RNA[blank_end] virus -with [blank_start]helical[blank_end] symmetry of the capsid. -It has a [blank_start]positive[blank_end], [blank_start]single-stranded[blank_end], [blank_start]non-segmented[blank_end] genome. -It is virion polymerase [blank_start]negative[blank_end]. -It's genome size is [blank_start]16-21[blank_end] kb.

The Reo family of viruses is classified as -[blank_start]Naked[blank_end] -[blank_start]RNA[blank_end] virus -with [blank_start]Icosahedral[blank_end] symmetry of the capsid. -It has a [blank_start]double-stranded[blank_end], [blank_start]10-18 segment[blank_end] genome. -It is virion polymerase [blank_start]positive.[blank_end] -It's genome size is [blank_start]22-27[blank_end] total in kb.

The Calici family of viruses is classified as a: -[blank_start]Naked[blank_end] -[blank_start]RNA[blank_end] virus -with [blank_start]Icosahedral[blank_end] symmetry of the capsid. -It has a [blank_start]positive, single-stranded, non-segmented[blank_end] genome. -It is virion polymerase [blank_start]negative[blank_end]. -It's genome size is [blank_start]8[blank_end] total in kb.

The Picorna family of viruses is classified as a: -[blank_start]Naked RNA[blank_end] virus with [blank_start]Icosahedral[blank_end] symmetry of the capsid. -It has a [blank_start]positive, single-stranded, non-segmented[blank_end] genome. -It is virion polymerase [blank_start]negative[blank_end]. -It's genome size is [blank_start]7.2-8.4[blank_end] total in kb.

The Flavi family of viruses is classified as a(n): -[blank_start]Enveloped RNA[blank_end] virus with [blank_start]Icosahedral[blank_end] symmetry of the capsid. -It has a [blank_start](+) ss continuous[blank_end] genome. -It is virion polymerase [blank_start]negative[blank_end]. -It's genome size is [blank_start]10[blank_end] total in kb.

The Toga family of viruses is classified as a(n): -Enveloped RNA virus with Icosahedral symmetry of the capsid. -It has a (-) ss continuous genome. -It is virion polymerase negative.

Which family of viruses has the following characteristics? -Enveloped RNA virus with Icosahedral symmetry of the capsid. -It has a (+) ss 2 copies genome architecture. -It is virion polymerase positve.

Which of the following family of viruses have a (-) single stranded, non-segmented genome architecture? (Select all that apply)

Which of the following can the smallest possible genome size?

Adenoviruses is a kind of RNA virus

Herpes virus, Pox viruses, Togaviruses, and Rhabdoviruses are all enveloped viruses

Which of the following Naked DNA viruses have a linear genome architecture? (Select all that apply)

Filoviruses do not have virion polymerases.

The pox virus is a Helical enveloped DNA virus.

Which of the following does not go with the others?

The virus life cycle: 1. [blank_start]Attachment[blank_end] - virus [blank_start]binding[blank_end] to cellular receptor(s) 2. [blank_start]Entry[blank_end] - [blank_start]receptor-mediated[blank_end] endocytosis or fusion of viral envelope with cell membrane 3. [blank_start]Uncoating[blank_end] - [blank_start]depends on entry process[blank_end] 4. [blank_start]Replication[blank_end] - [blank_start]depends on type of virus[blank_end] • [blank_start]mRNA[blank_end] transcription • [blank_start]protein[blank_end] translation • [blank_start]nucleic acid[blank_end] replication 5. [blank_start]Assembly[blank_end] - depends on type of virus 6. [blank_start]Release[blank_end] - [blank_start]naked viruses[blank_end] generally release by cell [blank_start]lysis[blank_end]; enveloped viruses release by membrane budding

Types of Virus Infection [blank_start]Acute[blank_end] – infection of a permissive cell: results in virus production, may result in cell death (lytic infection) [blank_start]Abortive[blank_end] – infection of a non- or semi-permissive cell: block to virus production at some step so infection aborts [blank_start]Persistent[blank_end] – long-lasting virus infection. Can be chronic, latent or slow.

Persistent infections: • [blank_start]Chronic[blank_end]-low levels of virus produced over a long time, chronic virus production and reinfection of cells • [blank_start]Latent[blank_end]- virus goes dormant following primary infection, may reactivate infection at subsequent times • [blank_start]Slow[blank_end]: virus production increases slowly over time

Productive infection- Sequence of events 1. [blank_start]Virus enters susceptible cells[blank_end] 2. [blank_start]Replication: Transcription / translation[blank_end] of viral genes 3. Viral [blank_start]genome replication occurs[blank_end] 4. [blank_start]Assembly, maturation, and release[blank_end] of virus particles 5. Generally (but not always) [blank_start]results in death[blank_end] of the host cell

Latent Infection: Sequence of events 1.Virus [blank_start]enters susceptible cells[blank_end] 2. [blank_start]Transcription / translation of latency[blank_end] associated viral genes Viral genes for lytic replication not expressed 3.[blank_start]Maintenance of the viral genome[blank_end] 4. [blank_start]No progeny virions produced[blank_end] 5. [blank_start]Reactivation of viral gene expression[blank_end] results in lytic gene expression and production of infectious virus