Test 1 Flashcards
(162 cards)
1
Q
The first pandemic ever recorded was caused by _________ virus in 1590 when it spread from Russia to Europe.
A
Influenza Virus
2
Q
The most lethal outbreak on record killed 50-100 million people in 1918. What virus caused it?
A
Influenza Virus
3
Q
_________ was the first method used to immunize a person against Smallpox
A
Variolation/Inoculation
4
Q
Who invented the smallpox vaccine by using “cowpox material”?
A
Edward Jenner
5
Q
Who invented the rabies vaccine after injecting a rabbit’s brain with potassium hydroxide?
A
Louis Pasteur
6
Q
Who invented the filter with pores smaller that bacteria?
A
Charles Chamberland
7
Q
Who discovered the Tobacco Mosaic Virus?
A
Dmitri Ivanovski
DMitri –> Mosaic
8
Q
Who discovered the cause of foot-and-mouth disease by passing the virus through a filter?
A
Loeffler and Frosch
9
Q
Named “the conqueror of yellow fever”, who discovered that yellow fever was spread by mosquitoes?
A
Dr. Walter Reed
10
Q
Who discovered oncogenic viruses and subsequently won a Nobel Prize for its discovery?
A
Peyton Rous
11
Q
Which two scientists invented the Electron Microscope?
A
Ruska and Knoll
MERK
Microscope Electron invented by Ruska and Knoll
12
Q
Woodruff, Goodpasture, and Burnet propagated this virus in embryonated eggs.
A
Fowlpox virus
13
Q
What is the difference between a virion and a virus?
A
A virion is the complete, mature, infective form of a virus.
A virus is a broad, general term that describes any aspect of the infectious agent
14
Q
What is the name for an infectious particle, smaller than any known viruses, and is an agent of plant disease?
A
Viriod
15
Q
When was the last reported outbreak of the now eradicated virus Rinderpest?
A
Kenya in 2001
16
Q
What is the very smallest virus, at 17 nm?
A
Porcine circovirus type 1
17
Q
What is the very largest virus at 400 nm?
A
Pandoravirus
18
Q
Spherical viruses, like Rotavirus have what kind of symmetry?
A
Cubic/Icosahedral
19
Q
The ability of some viruses to alter their size or shape is called _________.
A
Pleiomorphism
20
Q
What are the four methods used to determine morphology of Viruses?
A
EM
Cryo-EM
X-Ray Crystallography
NMR
21
Q
Most viruses have 1 capsid. What is the exception?
A
Reoviruses have 2 capsids
22
Q
What is the basic subunit protein of the viral capsid?
A
Capsomere
23
Q
All animal nucleocapsids with helical symmetry have what?
A
A lipoprotein envelope
24
Q
What kind of viruses have naked helical nucleocapsids?
A
Plant Viruses like the Tobacco Mosaic Virus
25
An Icosahedron is a solid with \_\_\_\_vertices, \_\_\_\_\_facets, and \_\_\_\_\_edges.
12 corners/vertices, 20 facets, 30 edges
26
The number of which type of capsomere, a penton or a hexon, varies with the virus group?
The # of hexons varies, the pentons are always at the 12 vertices
27
Only _______ viruses have icosahedral symmetry
Spherical
28
What is the formula for calculating T number?
T= (h)2 + (h)(k) + (k)2
h and k are jumps from penton to penton in different directions
29
What is the simplest icosahedron virus with its T number equal to 1 and 60 copies of capsomere protein?
Parvovirus
30
For Reoviridae, what is the T number for the outer capsid? The inner capsid?
```
Outer = 13
Inner = 2
```
31
Poxviruses and Bacteriophage have what kind of symmetry?
Complex symmetry
32
The capsid serves as a core of replication in what two viruses?
Reovirus and Retrovirus
33
Does a naked virus or an enveloped virus cause persistent infections?
Enveloped virus
34
What embedded envelope protein serves as the major antigens of the virus?
Glycoprotein (external)
35
What embedded envelope protein plays a crucial role in virus assembly?
Matrix Protein
36
Hemagglutin (HA) and Neuramidase (NP) are examples of what kind of envelope protein?
Viral envelope glycoproteins
37
Fusion proteins can be pH dependent or pH independent. Name two viruses with pH independent fusion proteins.
HIV and Measles
38
Which is easier to sterilize: enveloped or non-enveloped viruses?
Enveloped viruses are easier to sterilize
39
Which survives longer in the environment: enveloped or non-enveloped viruses?
Non-enveloped viruses survive longer in the environment
40
What kind of solvents can inactivate an enveloped virus?
Lipid solvents
41
Which sense of viral RNA is considered the infectious genome?
(+) sense viral RNA is the infectious genome
42
What mechanism of viral genetic diversity can lead to virus resistance to antiviral drugs?
Antigenic Drift can cause virus resistance.
43
Reassortment and Recombination are types of what mechanism of genetic diversity?
Reassortment and Recombination are forms of Antigenic SHIFT
44
What is the most important mechanism for high genetic diversity?
Reassortment – Antigenic Shift
Re**ass**ortment
"*Look at dat **ass** in those genes"*
45
What is the smallest, double stranded, circular DNA virus at 5 kbp?
Polyomaviridae
46
What is the largest, double stranded, linear DNA virus at 235 kbp?
Herpesvirinae
47
What is the smallest RNA virus at 2 kbp?
Deltavirus
48
What is the largest RNA virus at 30 kbp?
Coronaviridae
49
Viral proteins make up what percent of the virion?
50-70%
50
VP7 and VP4 are examples of ________ proteins that form the capsid in Rotavirus
VP7 and VP4 are _structural_ proteins
51
NSP1 – NSP5 are examples of \_\_\_\_\_\_\_\_proteins in Rotavirus; proteins that are encoded by the virus but made in the host cell
NSP1 - NSP5 are _nonstructural_ proteins
52
What are the 4 aberrations in virus morphology?
Incomplete virions
Defective virions
Pseudovirions
Pseudotypes
Gotta do DIPPs to get good abs
53
A virion without a nucleic acid, also known as an empty capsid, is called what?
Incomplete virion
54
A virus that cannon replicate because it lacks a full copy of genes is called what?
Defective virion
55
What is a DIP? What does it do?
Defective Interfering Particle
A defective virion that cannot replicate, but can interfere with other mature viruses entering cells
56
What type of aberration in virus morphology is used to deliver DNA vaccines? Why?
Pseudovirions
Because it is a nonviral genome inside a viral capsid
57
When two viruses infect the same cell and the genome of one virus gets into the capsid of the other, what is this called?
Pseudotypes
58
What are two names for the disease in pigs caused by Pestivirus?
Hog Cholera
Classical Swine Fever
59
The Baltimore Classification System categorizes viruses based on viral genome into how many groups?
7 groups
60
Double stranded DNA is classified into which group of the Baltimore Classification System?
Group 1
61
Single stranded DNA is classified into which group of the Baltimore Classification System?
Group 2
62
Double stranded RNA is classified into which group of the Baltimore Classification System?
Group 3
63
Single stranded RNA (+) sense is classified into which group of the Baltimore Classification System?
Group 4
64
Single stranded RNA (-) sense is classified into which group of the Baltimore Classification System?
Group 5
65
(+) single stranded RNA with a DNA intermediate is classified into which group of the Baltimore Classification System?
Group 6
66
Double stranded DNA with a single stranded RNA intermediate is classified into which group of the Baltimore Classification System?
Group 7
67
According to the ICTV, an _order_ ends with the suffix \_\_\_\_\_\_?
–virales
68
According to the ICTV, a _family_ ends with the suffix \_\_\_\_\_\_?
–viriDae
69
According to the ICTV, a subfamily ends with the suffix \_\_\_\_\_\_?
–viriNae
70
According to the ICTV, a genus ends with the suffix \_\_\_\_\_\_\_?
–virus
71
This family of viruses is characterized by having an envelope and being single stranded. This RNA virus family includes BVD, Hog Cholera, West Nile Virus, Louping Ill, and Equine Arteritis Virus. What is it?
Family Flaviviridae
72
Scrapie, Bovine Spongiform Encephalopathy, and Mad Cow Disease are all caused by what?
Prions
73
What are 4 ways to grow and cultivate viruses?
Cell/Tissue Culture
Inoculation in Embryonated Egg
Lab Animals
Organ Culture
74
Can viruses reproduce via binary fission?
NO
75
What are the 3 types of cell culture?
Primary cell culture
Secondary/Transfer cell culture
Cell lines
76
What kind of cell culture is best for isolating and propagating viruses?
_Primary cell culture_ is best for isolating and propagting viruses
77
What kind of cell culture is used for *making vaccines*?
_Primary cell culture_ is used for making vaccines
78
After the first subculture, a primary cell culture becomes a ______ \_\_\_\_\_\_\_
cell line
79
How many subcultures can you take from a primary cell culture?
5 - 20 subcultures
80
How many subcultures can you take from a Finite Diploid Cell Line?
100 subcultures
81
What are Finite Diploid Cell Lines derived from?
Embryos or Secondary Cell Cultures
82
WI-38 is a cell culture line made of fibroblasts, derived from the lung tissue of a 3 month old white female fetus. What kind of cell line is WI-38?
WI-38 is a Finite Diploid Cell Line
83
What kind of cell line exhibits *contact inhibition *and *anchorage dependence*?
Finite Diploid Cell Line
exhibits contact inibition and anchorage dependence
84
Continuous Cell Lines, also known as Immortal or Heteroploid Cell Lines, are derived from what kind of cells?
Continuous cell lines are derived
from _cancer_ _cells_
85
Which type of cell line has a rapid growth rate, with doubling time from 12 to 24 hours?
Continuous cell line
86
HeLa Cells (Henrietta Lacks) are an example of what kind of cell line?
HeLa cells are an example of a
## Footnote
*Continuous cell line*
87
The FDA prohibits the use of this cell line in vaccines
Continuous cell lines
are prohibited from being used in vaccines
88
A cell in cell culture is seen with the following morphology:
Bipolar or multipolar
Elongated shape
Growing attached to a substrate
What kind of cell is it?
If the cell is bipolar or multipolar with an elongated shape and growing attached to a substrate, the cell is considered
_Fibroblastic_
89
A cell in cell culture is seen with the following morphology:
Polygonal in shape
Regular dimensions
Growing in patches attached to a substrate
What kind of cell is it?
A polygonal cell in culture with regular dimensions seen growing in patches attached to a substrate is an
_Epithelial-like cell_
90
A cell in cell culture is seen with the following morphology:
Spherical in shape
Growing in a *suspension* and not attached to any substrate
What kind of cell is it?
A spherically shaped cell seen growing in a suspension has
_Lymphoblast-like_
morphology
91
There are 3 kinds of morphologies seen in cells in culture: Fibroblastic, Epithelial-like, and Lymphoblast-like. Which one is the only one seen growing *unattached to a substrate* aka in a *suspension*?
Lymphoblast-like
92
What is the purpose of cell culture media?
Cell culture media provides all the necessary nutrients required for a cell to grow
Amino acids
Inorganic salts
Vitamins
Glucose
93
_Serum_ is a source of what 4 things?
1. Adhesion factors
2. Attachment factors
3. Nutrients
4. Growth factors
94
What is the *most *widely used *serum supplement*?
FBS
| (Fetal Bovine Serum)
95
Growth medium is \_\_\_\_% serum
Growth medium is *5-10% *serum
96
Maintenance Medium is \_\_\_\_% serum
Maintenance Medium is *0-2% *serum
97
If you're using *Phenol Red pH Indicator *and your culture turns **RED**, what does this tell you about your culture?
**RED = Basicity (Alkalinity)**
Your culture has a pH greater than 7
98
If you're using *Phenol Red pH Indicator *and your culture turns **YELLOW**, what does this tell you about your culture?
**YELLOW = Acidic**
Your culture has a pH less than 7
99
What is HEPES?
An organic buffer used to control the pH of culture
100
What % of CO2 is considered normal for cell culture?
*4-10% *CO2 is considered normal
101
Gentamicin Sulfate and Kanamycin Monosulfate are examples of what?
_Antimicrobial agents_ used to prevent contamination from
Bacteria, mycoplasma, yeast, and mold
102
Damage or morphological changes to host cells during virus invasion is called what?
Cytopathic Effect (CPE)
103
Cellular vacuolization, the opening of intercellular junctions, and cell detachment are examples of what?
Cytopathic Effect (CPE)
104
What kind of techniques would you use for *rapid cell culture*?
Use the _Shell Vial Technique_ or _Co-Cultivated Cell Technique_ for rapid cell culture
105
What type of rapid cell culture is ideal for the isolation of multiple viruses?
Co-Cultivated Cells Technique
106
What is **R-MIX **and what is it used for?
R-mix is a mixed monolayer of mink lung cells and human adenocarcinoma cells
It is used for Co-Cultivated Cell Technique in the detection of viral antigens
107
In *egg candling*, a method of cultivating viruses in eggs, what does a *blood ring *indicate?
A blood ring indicates a
_dead embryo_
;(
108
What are the 4 routes of egg inoculation?
Chorioallantoic Membrane Inoculation (CAM)
Amniotic Inoculation
Allantoic Inoculation
Yolk-Sac Inoculation
109
What does it mean if you see any of the following in an egg inoculation?
## Footnote
Death of embryo Urate deposits in mesonephros
Paralysis or sluggish movement Hemorrhage and congestion
Stunted growth Hemagglutins in embryonic fluid
Urate deposits in mesonephros Extracellular Membrane lesions
Pocks on Chorioallantoic Membrane (CAM)
All of these things indicate
_virus growth_
in egg inoculation
110
What type of centrifugation is based on buoyancy?
*Isopycnic Centrifugation*
is based on buoyancy
111
The point where the buoyant density of the particle equals the surrounding Density Gradient Medium is called what?
The *isopycnic point *is when
buoyant density = surrounding density of the medium
112
What two substances can you use for a
Density Gradient Medium?
_Sucrose and Cesium chloride_
can be used as
Density Gradient Mediums
113
The *lowest concentration *of a virus that *still infects* cells is the what?
The _Virus Titer_ is
the LOWEST concentration of a virus that still infects cells
114
The *# of infectious units *per mL of sample is known as
_Virus Titer_
Virus Titer = #infectious units/mL of sample
115
Plaque Assays
Pock Assays
Endpoint Titration Methods
are examples of this type of viral quantification test
_Biological Quantification Tests_
include Plaque and Pock Assays
& Endpoint Titration Methods
116
What are the 5 Physical Quantification Tests?
Flow **C**ytometry
**H**emagglutination
**I**mmunological Assays (ELISA)
Quantitative **P**CR Analysis
**E**M Particle Count
_Remember the Physical Quantification Tests by_
_using **CHIPE**_
117
What is the most *direct *method to determine concentration of virus particles in solution?
TEM
(Transmission Electron Microscopy)
is the most direct method to determine concentration of virus particles in solution
118
What type of virus quantification is *ideal *for viruses with *unique shapes*?
TEM
(Transmission Electron Microscopy)
is great for viruses that have strange shapes!
119
Hemagglutination Assay, ELISA, HPLC, and SRID are all tests based on what property?
* Hemagglutination Assay
* ELISA
* HPLC (high performace liquid chromatography)
* SRID (Single Radial Immunodiffusion)
are all tests based on...
**_Antigen Concentration!_**
120
The *inverse *of the *greatest dilution *that completely *agglutinates* the RBC's of the virus suspension is known as what?
**HA Titer **
HA Titer = 1 / (greatest agglutinated dilution)
121
What is the only quantification test based on *gene expression*?
**qPCR **
is based on *gene expression*
*"OMG those genes are sooo Qute!"*
122
A circular zone of necrotic cells
surrounded by viable cells
in a monolayer
is called?
**Plaque**
circular zone of necrotic cells surrounded by viable cells in a monolayer
123
What type of viral quantification test is considered the simplest and *most accurate of the biological assays*?
**Monolayer Plaque Assay**
is the simplest and most accurate!
124
What is the *Principle of Plaque Assay*?
The Principle of Plaque Assay states that
each plaque represents cell lysis
initiated by 1 viral particle
125
How do you calculate the Titer in a monolayer plaque assay?
take the average of the plaque counts
and multiply by
the reciprocal of the dilution selected
x + y / 2 = Average Plaque Count (APC)
1/ mL = Reciprocal Dilution (RD)
**APC x RD = Titer**
126
Necrotic area on chorioallantoic membrane (CAM) of an embryonated egg is known as
a **POCK**
necrotic area on CAM of an egg
127
What is the difference between a *plaque *and a *pock *?
A *plaque* is a necrotic area in a *monolayer*
A *pock *is a necrotic area in the *CAM* of an egg
128
What quantification test is used to determine *titers *of *oncogenic viruses* ?
Transformation Assay
is used to figure out the TITER of ONCOGENIC viruses
129
Oncogenic viruses *transform *cells in culture. What do you see with transformed cells?
**Loss of contact inhibition **
and
the cells will
**heap-up on one another**
130
What kind of assay is used for quantification of viruses that *DO NOT form plaques*?
Quantal Assays
used for viruses that do NOT form plaques
131
The virus dilution that affects 50% of test subjects is called the
Endpoint
132
What does TCID50 tell you?
It is the **t**issue **c**ulture **i**nfective **d**ose that will infect **50**% of cell monolayers presented with the virus
133
What is the MOI?
MOI is the *multiplicity of infection*
It is the average # of virus particles infecting each cell
134
How do you calculate TCID50?
What method is used to calculate it?
Use the **Reed and Muench Method**
_(%infected *above* 50%) - 50_
(%infected *above* 50%) - (%infected *below* 50%)
Then, add the # you get to the dilution above 50%
So if you get 0.3 for your answer and the dilution is 10-2, the Titer = 10-2.3 TCID50/0.1 mL
135
The *burst size *= the *height of the curve*
But what does this tell you?
The burst size or the height of the curve tells you
_the # of virions released_
136
In the One-Step Virus Growth Curve
the time between uncoating and appearance of virions in the cell
is called
The Eclipse Period
137
Can you detect viruses in the Eclipse Period?
NO, you cannot detect viruses during the Eclipse Period
138
In the One-Step Virus Growth Curve
the time before new infectious virus appears in medium
is called
The Latent Period
139
What kind of viruses are detectable during the Latent Period
in the One-Step Virus Growth Curve?
Only *intracellular virions *are detectable during the Latent Period
140
True or False
You can detect extracellular viruses during the Latent Period
in the One-Step Virus Growth Curve
FALSE
You can only detect *intracellular viruses *during the
Latent Period
141
What are the 6 steps of Virus Replication?
Attachment
Penetration
Uncoating
Synthesis of Viral mRNA
Assembly and Maturation
Release in large #s
**APUSAR**
A Puppy Uses Shoes As Relaxation
142
What are the 4 methods of Virus Penetration?
Endocytosis
Surface Fusion
Pore-Mediated
Antibody-Mediated
**APES penetrate**
143
What are the 2 types of Receptor-Mediated Endocytosis?
A1 Clathrin-mediated endocytosis
and
Caveolin-mediated endocytosis
144
What kind of receptor-mediated endocytosis causes the pH in the endosome to change to *acidic*?
A1-Clathrin-mediated endocytosis
involves a step where the pH changes to *acidic *
in the endosome
**A**1 = **a**cidic
145
Which method of virus penetration is reserved for ONLY *enveloped viruses*?
Surface Fusion
is only achieved by *enveloped *viruses
146
What method of virus penetration is reserved for ONLY
***non****enveloped viruses*?
Pore-Mediated Penetration
is only accomplished by
***non**enveloped viruses*
147
Feline Infectious Peritonitis Virus uses which method of virus penetration?
FIP uses _Antibody-Mediated Penetration_
by using **CD13 **receptor and
**IgG-Fcŷ**
148
What stage of Virus Replication causes a
*loss of infectivity* of virions?
**Uncoating**
causes a loss of infectivity
149
What are the 3 steps of Primary RNA Transcript Processing?
Capping
Addition of Tails
Splicing
150
Capping refers to the addition of *7-methylguanosine *to the
\_\_\_' end of RNA
Capping refers to the addition of *7-methylguanosine* to the
**_5'_ **end of RNA
151
How many residues does the *3'-poly-adenylated tail* have?
The *3'-poly-adenylated tail *has **250 A residues**
152
What is the 3' cleavage sequence?
**AAUAAA**
153
After the AAUAAA cleavage sequence, how many nucleotides downstream does the actual cleavage occur?
**10-35 nucleotides downstream from AAUAAA**
154
What is it called when you remove introns and join exons?
Splicing
* Remove *Introns
* Join *Exons
(Remove and Intron have the same # of letters)
(Join and Exon have the same # of letters)
155
Does an intron or exon encode for amino acids?
**Exons** encode for amino acids
156
When **every** intron is spliced out and **every** exon is spliced in, what kind of splicing is it?
Constitutive Splicing
157
During the release step of virus replication, what happens to the host cell of a **naked **virus?
The host cell is **lysed**
for a naked virus
158
How are **enveloped** viruses released from their host cell during virus replication?
Enveloped viruses use **Budding **to release from their host cell
159
Monocistronic and Polycistronic are types of what?
Monocistronic and Polycistronic are types of
**Viral mRNA**
that encode either one or multiple polypeptides
160
What are the 4 methods of Cell-to-Cell Spread of Viruses?
Extracellular
Intercellular
Intercellular Transmission
Nuclear
161
What type of Cell-to-Cell Spread of Viruses
results in
rapid virus dissemination, evasion of the immune system, and persistent infections?
**Intercellular spread**
results in
rapid virus dissemination, evasion of the immune system, and persistent infections
162
What kind of Cell-to-Cell Spread of Viruses refers to the
viral genome being integrated into the host genome
and is subsequently passed down to the next generation
of host cells?
**Nuclear Spread **of Viruses
involves integration of viral genome into host cell genome
and generational transfer
