9.1 VIRO INTRO

Question 1

What is the smallest infectious agent?

Answer 1

Viruses

Question 2

What is the size range of viruses?

Answer 2

20 nm to 300 nm in diameter

Question 3

Which virus is the only one visible under a light microscope?

Answer 3

Pox virus

Question 4

Which virus is the largest of all viruses?

Answer 4

Pox virus

Question 5

What type of microscope is typically used to view viruses?

Answer 5

Electron microscope

Question 6

Where are electron microscopes commonly found?

Answer 6

Research-based laboratories

Question 7

What are viruses made of?

Answer 7

One type of nucleic acid (RNA or DNA) encased in a protein shell

Question 8

Which nucleic acid does SARS-CoV-2 contain?

Answer 8

RNA

Question 9

Which nucleic acid do hepatitis B, herpes, pox, papilloma (HPV), and parvovirus contain?

Answer 9

DNA

Question 10

Why are viruses considered intracellular parasites?

Answer 10

They are inactive outside the host and replicate only in living cells

Question 11

What is the mode of virus multiplication?

Answer 11

Replication of genome inside a host cell

Question 12

What are the two main types of viral structures?

Answer 12

Icosahedral (Piattos-like) and Helical (coil-like)

Question 13

What are the two types of viral envelopes?

Answer 13

Enveloped and Non-enveloped (naked)

Question 14

What are the two types of viral genomes?

Answer 14

RNA and DNA

Question 15

Can a virus contain both RNA and DNA?

Answer 15

No

Question 16

What are the two strategies of viral replication?

Answer 16

Positive sense and Negative sense

Question 17

What determines the host range of a virus?

Answer 17

Receptor specificity (Lock and Key Theory)

Question 18

What type of viruses infect bacteria?

Answer 18

Bacteriophages

Question 19

What is an example of a virus with a specific host range?

Answer 19

HIV (infects immune cells like lymphocytes and macrophages)

Question 20

Protein shell, or coat, that encloses the nucleic acid genome

Answer 20

Capsid

Question 21

Clusters of polypeptides that do not necessarily correspond to chemically defined structural units

Answer 21

Capsomeres

Question 22

Virus particle that is functionally deficient in some aspect of replication

Answer 22

Defective virus

Question 23

An example of a defective virus that requires hepatitis B virus to replicate

Answer 23

Hepatitis D

Question 24

The specific component that hepatitis D lacks

Answer 24

Hepatitis B surface antigen (HBsAg)

Question 25

Lipid-containing membrane that surrounds some virus particles

Answer 25

Envelope

Question 26

Process by which viruses acquire an envelope from the host cell

Answer 26

Budding

Question 27

Virus-encoded glycoproteins exposed on the surface of the envelope

Answer 27

Peplomers

Question 28

The packaged form of the viral genome consisting of protein and nucleic acid

Answer 28

Nucleocapsid

Question 29

Basic protein building blocks of the viral coat, made of more than one nonidentical protein subunit

Answer 29

Structural units (Protomer)

Question 30

A single folded viral polypeptide chain

Answer 30

Subunit

Question 31

A complete virus particle that transfers viral nucleic acid from one cell to another

Answer 31

Virion

Question 32

Viruses in which the virion is identical to the nucleocapsid

Answer 32

Papillomaviruses, Picornaviruses

Question 33

Viruses in which the nucleocapsid is separate from the envelope

Answer 33

Herpesviruses, Orthomyxoviruses

Question 34

Theory stating that viruses originated from host DNA or RNA components that evolved to replicate independently

Answer 34

First theory of viral origin

Question 35

Theory stating that viruses may be degenerate forms of intracellular parasites

Answer 35

Second theory of viral origin

Question 36

The structural classification of a virion as either icosahedral or helical

Answer 36

Virion morphology

Question 37

The classification of a virus based on whether it has RNA or DNA

Answer 37

Virus genome properties

Question 38

The classification of a virus based on its susceptibility to ether or organic solvents

Answer 38

Physicochemical properties

Question 39

The type of viruses that are susceptible to destruction by organic solvents like ether and alcohol

Answer 39

Enveloped viruses

Question 40

The classification of a virus based on the structure and function of its proteins

Answer 40

Virus protein properties

Question 41

The classification of a virus based on how its genome is organized and replicated

Answer 41

Genome organization and replication

Question 42

The classification of a virus based on its antigenic makeup

Answer 42

Antigenic properties

Question 43

The classification of a virus based on its biological behavior, such as host range and transmission

Answer 43

Biologic properties

Question 44

The hierarchical system that divides viruses into orders, families, subfamilies, genera, and species

Answer 44

Universal system of virus taxonomy

Question 45

The category in viral taxonomy that groups virus families sharing common characteristics

Answer 45

Order

Question 46

An example of an order that includes Bornaviridae, Filoviridae, Paramyxoviridae, and Rhabdoviridae

Answer 46

Mononegavirales

Question 47

The major viral grouping based on virion morphology, genome structure, and replication strategy

Answer 47

Family

Question 48

The viral classification that subdivides families based on biological, genomic, physicochemical, or serologic differences

Answer 48

Genus

Question 49

The symmetry and shape of all DNA viruses except pox viruses

Answer 49

Icosahedral

Question 50

The symmetry and shape of pox viruses

Answer 50

Complex and brick-shaped

Question 51

The symmetry of most RNA viruses except picornaviruses

Answer 51

Helical

Question 52

The only RNA virus family that has a double-stranded RNA genome

Answer 52

Reoviridae

Question 53

The human virus that infects immature erythrocytes and causes 'slap cheek disease'

Answer 53

Parvovirus B19

Question 54

The virus family under picornaviruses

Answer 54

Polyomaviridae

Question 55

The HPV types associated with cervical cancer

Answer 55

HPV 16 and 18

Question 56

The only viral family that includes a virus causing hepatitis

Answer 56

Hepadnaviridae