Virology intro

Question 1

an obligate intracellular parasite, that is among the smallest of all infectious agents and capable of infecting an animal, insect, plant, or bacterial cell.

Answer 1

Virus

Question 2

The emergence of a new viral disease across a very large geographic region (worldwide) with prolonged human-to-human transmission

Answer 2

Pandemic

Question 3

Incapable of replication without a
living host cell

Answer 3

Virus

Question 4

Replicate only in living cells

Answer 4

Virus

Question 5

Only contain one nucleic acid (DNA or RNA)

Answer 5

Virus

Question 6

Viruses are inert in extracellular environment

Answer 6

Virus

Question 7

Most of the pandemics recorded had been caused by an _____________

Answer 7

Influenza virus

Question 8

Major change in the nucleic acid of a virus.

Answer 8

Genetic virus

Question 9

major changes that result in novel viral antigens

Answer 9

Antigenic shift

Question 10

minor changes that occur continuously over time as the virus replicates

Answer 10

Antigenic drift

Question 11

The protein shell, or coat, that encloses the nucleic acid genome.

Answer 11

Capsid

Question 12

Morphologic units seen in the electron microscope on the surface of icosahedral virus particles.

Answer 12

Capsomeres

Question 13

represent clusters of polypeptides, but the morphologic units do not necessarily correspond to the chemically defined structural units.

Answer 13

Capsomeres

Question 14

A virus particle that is functionally deficient in some aspect of replication.

Answer 14

Defective virus

Question 15

The basic protein building blocks of the coat.

Answer 15

Structural units

Question 16

They are usually a collection of more than one nonidentical protein subunit. The structural unit is often referred

Answer 16

protomer

Question 17

A single folded viral polypeptide chain.

Answer 17

Subunit

Question 18

The complete virus particle.

Answer 18

Virion

Question 19

Basic classification of virology

Answer 19

Virion morphology
Virus genome properties
Genome organization and replication
Virus protein properties
Antigenic properties
Physicochemical properties of the virion
Biologic properties

Question 20

tend to be stable,losing little infectivity after several hours at 37°C

Answer 20

Icosahedral

Question 21

are much more heat labile, rapidly dropping in titer at 37°C

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Enveloped

Question 22

Reaction to Physical and Chemical Agents

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Heat and cold
Stabilization of Viruses by Salts
pH
Radiation
Ether Susceptibility
Detergents
Formaldehyde
Photodynamic Inactivation
Antibiotics and Other Antibacterial Agents

Question 23

Viral infectivity is generally destroyed

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heating at 50-60°C for 30 minutes

Question 24

usually stable between pH values of

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5.0 and 9.0

Question 25

‼️‼️‼️REMINDER‼️‼️‼️‼️ All viruses are destroyed by alkaline condition

Question 26

Many viruses can be stabilized by salts in concentrations of

Answer 26

1 mol/L

Question 27

Can be used to distinguish viruses that possess an envelope from those that donot

Answer 27

Ether Susceptibility

Question 28

solubilize lipid constituents of viral membranes

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Nonionic detergents

Question 29

also solubilize viral envelopes

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Anionic detergents

Question 30

Destroys viral infectivity by reacting with nucleic acid

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Formaldehyde

Question 31

Viruses are penetrable to a varying degree by vital dyes such as

Answer 31

toluidine blue neutral red proflavine

Question 32

Common Methods of Inactivating Viruses for Various Purposes

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Sterilization Surface disinfectants Skin disinfectants Vaccine production may involve the use of

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Sterilization

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- steam under pressure - dry heat - ethylene oxide - > y-irradiation

Question 34

Surface disinfectants

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- sodium hypochlorite - glutaraldehyde - formaldehyde - peracetic acid

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Skin disinfectants

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- chlorhexidine - 70% ethanol - iodophors

Question 36

Vaccine production may involve the use of

Answer 36

- formaldehyde - b-propiolactone - psoralen + ultraviolet irradiation - detergents

Question 37

Viral Replication

Answer 37

Attachment Penetration Uncoating Macromolecular synthesis Viral assemble Release

Question 38

First step of the infectious cycle

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Attachment (absorption)

Question 39

One mechanism of penetration is fusion of the viral envelope with the host cell membrane

Answer 39

Penetration (virus entry or engulfment)

Question 40

Occurs once the virus are being internalized

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Uncoating

Question 41

Physical separation of the viral nucleic acid from the outer structural components of virion

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Uncoating

Question 42

Production of nucleic acid and protein polyester

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Macromolecular synthesis

Question 43

Process by which structural proteins, genomes and in some cases viral enzymes are assembled into virus particles

Answer 43

Viral assemble

Question 44

‼️‼️‼️Reminder‼️‼️‼️ Acquisition of an enveloped is the final step in viral assemble

Question 45

Viral Detection Methods

Answer 45

1. Cytology and Histology 2. Immunodiagnostics (Antigen Detection) 3. Enzyme-Linked Virus-Inducible System 4. Nucleic Acid Based Methods 5. Cell Culture 6. Matrix-Assisted Desorption lonization Time-of-Fligh Mass Spectrometry