Virology 1: Intro to Veterinary Virology

Question 1

Describe the characteristics unique to viruses

Answer 1

smallest infectious particles
range from 18-300 nm
consist of RNA OR DNA and proteins with or without lipid membrane coat
lack independent metabolic system
require host cell for replication
consist of intracellular repro cycle and an extracellular transmissive cycle

Question 2

What is the typical range in size for a virus

Answer 2

18-300 nm

Question 3

Do viruses consist or RNA or DNA

Answer 3

EITHER OR - NEVER BOTH

Question 4

What do viruses lack

Answer 4

independent metabolic system

Question 5

What do viruses require for replication

Answer 5

host cell

Question 6

Why are viruses considered to be true parasites

Answer 6

require host cell for replication

Question 7

Which microorganims multiplies by binary fission: unicellular or viruses

Answer 7

unicellular

Question 8

What are prions

Answer 8

Proteins that exist normally in the cells but have ability to misfold and cause disease

Question 9

Prions that exist normally in the body are ____ and prions that are abnormal and have conformational aberration are _____

Answer 9

Normal = PrPc
Abnormal = PrPsc

Question 10

What is the difference between a virus and a prion?

Answer 10

a virus is an infectious particle that contains a nucleic acid particle covered by a protein core
a prion is a simpler infectious particle that is made up of only proteins

Question 11

What is the difference between an enveloped virus and a non-enveloped virus in terms of survival and pathogenesis

Answer 11

enveloped viruses have short survival in environment, and labile, and are easier to inactivate whereas non-enveloped viruses are more resistance, and have longer survival in environment
Enveloped viruses bud through infected cells leading to chronic/persistent infections whereas non-enveloped viruses have lytic infection and are often associated with acute disease

Question 12

Which type of virus is associated with seasonal disease?

Answer 12

enveloped viruses

Question 13

Which type of virus lasts longer in the environment?

Answer 13

non-enveloped virus

Question 14

Which type of virus is easier to inactivate?

Answer 14

enveloped virus

Question 15

Which type of virus buds through infected cells and is chronic or more persistent?

Answer 15

enveloped virus

Question 16

Which type of virus has only the nucelocapsid protein and is considered “naked”?

Answer 16

non-enveloped

Question 17

What is the correct taxonomy of viruses?

Answer 17

order, family, genera, species

Question 18

What is the nomenclature of virus order?

Answer 18

virales

Question 19

What is the nomenclature of virus family?

Answer 19

viridae

Question 20

What is the correct nomenclature of virus genera?

Answer 20

virus

Question 21

What is the correct nomenclature of virus species?

Answer 21

Strain

Question 22

What taxonomy would arteriviridae be considered under?

Answer 22

family

Question 23

What taxonomy would nidiovirales be considered under?

Answer 23

order

Question 24

What taxonomy would arterivirus be considered under?

Answer 24

genera

Question 25

What taxonomy would equine arteritis virus be considered under?

Answer 25

species

Question 26

What are the building blocks of non-enveloped viruses?

Answer 26

Protein subunit Structure unit Capsomer Capsid (coat or shell) nucleocapsid

Question 27

What are the building blocks of enveloped viruses?

Answer 27

Protein subunit Structure unit Capsomer Capsid (coat or shell) nucleocapsid + ENVELOPE

Question 28

What does the envelope of a virus contain

Answer 28

peplomer/spike carbs, glycoproteins, and phospholipids

Question 29

What are structural proteins

Answer 29

virion proteins containing: capsid/nucleocapsid: protecting genome envelope protein (spike, matrix), ligands( VAPs)

Question 30

What are non-structural proteins

Answer 30

enzymes, replication, regulatory proteins -polymerases/transcriptases -reverse transcriptase -integrase

Question 31

What does the non-structural protein polymerase do?

Answer 31

turns dsDNA/dsRNA to mRNA

Question 32

What does the non-structural protein reverse transcriptase do?

Answer 32

retroviruses from RNA to DNA

Question 33

What does the non-structural protein integrase do?

Answer 33

integrates proviral DNA of retroviruses into host genome

Question 34

Is DNA double or single stranded? What about RNA?

Answer 34

DNA = ds RNA = ss

Question 35

What is the most common symmetry for DNA? RNA?

Answer 35

DNA = icosahedral RNA = helical

Question 36

What is the relative size of DNA to RNA?

Answer 36

DNA = bigger than RNA

Question 37

What symmetry do RNA and enveloped viruses have?

Answer 37

Helical

Question 38

Most DNA is icosahedral but ______ is an outlier and has complex symmetry

Answer 38

Poxvirus

Question 39

What are the 2 life cycles of viruses?

Answer 39

Extracellular (Transmissive, inert) Intracellular (reproductive)

Question 40

What are unconventional viruses (subviral particles)?

Answer 40

extremely simple, replicating agents, either nucleic acid or protein

Question 41

What are viroids/virusoids?

Answer 41

Plant pathogens

Question 42

Where do viroids replicate?

Answer 42

in the nucleus

Question 43

Where do virusoids replicate?

Answer 43

in the cytoplasm

Question 44

What are 2 types of subviral particles?

Answer 44

Viroids/virusoids Prions

Question 45

What are prions?

Answer 45

A small proteinaceous infecting particle with NO nucleic acid genome

Question 46

What is unique about prions?

Answer 46

resistance to heat, UV, irradiation, and chemicals

Question 47

What is the chemical composition of viruses

Answer 47

nucleic acids, proteins, carbs (glycoproteins), and lipids