Chapter 13- Viruses (EXAM 2) Flashcards
Where do viruses replicate?
only inside host cells
What two phases do viruses exist in?
A virus exists in two phases: intracellular (infected cell) where it is ‘alive,’ and extracellular (virion particle) where it is inactive.
How do viruses differ from bacteria?
Viruses are tinier than bacteria. All viruses have is a protein coat and a core of genetic material, either RNA or DNA. Unlike bacteria, viruses can’t survive without a host. They can only reproduce by attaching themselves to cells.
Are viruses living?
no
multiply inside living cells by using the energy,
metabolites, and biosynthetic machinery of the cell
obligatory intracellular parasites
do viruses make energy or ATP?
no
viruses are enclosed in a protein coat called a _______
capsid
Some viruses have a ______ envelope
lipid
Do viruses pass through a bacteriological filter?
yes
What are viruses made of?
a nucleic acid genome and a protein capsid or coat
virus nucleic acid is one molecule or several (__________ or _________)
much, much smaller than a single human chromosome
segmented or unsegmented
the genome plus the capsid
nucleocapsid
some viruses contain no __________
viral membranes (envelopes)
Some viruses also contain:
envelope or viral membrane taken from the host cell membrane proteins some encoded by the virus some belonging to the host polymerase RNA polymerase or DNA polymerase other virus-encoded proteins
How small are bacteriophages T4 and M13? and MS2
225nm; 800*10 nm; 24 nm
How small are adenovirus?
90 nm
how small are rhinovirus?
30 nm
How small are prions?
20 *20 nm
how small are vaccinia virus?
300200 100 nm
how small are viroid?
300 * 10 nm
how small is ebola virus?
970 nm
how small is an E.coli bacterium?
3000*1000 nm
how small is rabies virus?
170 * 70 nm
how small is rabies virus?
170 * 70 nm
How could the small size of viruses have helped researchers detect viruses before the invention of the electron microscope?
Filterable agents
What is the resolution on a light microscope?
0.2 microns or 200 nanometers
What is the resolution on a transmission electron microscopy?
0.2 nanometers
What is the X-ray crystallography?
0.05 nanometers, 0.5 angstrom
Where was the first electron microscope made?
In camden nj
What are the different virus shapes?
polyhedral w/ spikes or no spikes
helical
complex
A virus can be __________ or ___________
enveloped or non-enveloped
Examples of polyhedral viruses
mastadenovirus
poliovirus
What are the components of a simple polyhedral virus?
capsomere (makes up a capsid), nucleic acid
What is an icosahedron?
20 sides
What is a pentakis dodecahedron?
60 sides
What is the envelope made up of?
lipids, proteins, and carbohydrates
How do viruses multiply
by using the host cell’s synthesizing machinery to cause the specialized elements that can transfer the viral nucleic acid to other cells
What is host range?
the spectrum of host cells in which a virus can multiply
Most viruses infect only specific types of _______ in one host species
cells
What is the host range determined by?
- the specific attachment site on the host cell’s surface
2. the availability of the host cellular factors
What is viral size ascertained by?
electron microscopy
What is the virus range in size?
20 to 1000 nm in length
What is a virion?
a complete, fully developed viral particle composed of nucleic acid surrounded by a coat
The proportion of nucleic acid in relation to protein in viruses ranges from about ___% to about ____%
1; 50
the protein coat surrounding the nucleic acid of a virus
capsid
The capsid is composed of subunits, __________, which can be single type of protein or several types
capsomeres
The capsid of some viruses is enclosed by an envelope consisting of _______, ________, and ___________.
lipids, proteins, and carbohydrates
Some envelopes are covered with carbohydrate-protein complexes called _________
spikes
example of helical viruses
ebola virus
resemble long rods, and their capsids are hollow cylinders surrounding the nucleic acid
helical viruses
example of polyhedral viruses
adenovirus
are many sided and the capsid is icosahedron
polyhedral viruses
example of an enveloped polyhedral virus
herpesvirus simplexvirus
where does the virus envelope come from?
the host
Enveloped viruses are covered by an envelope and are roughly spherical but highly _________.
pleomorphic
example of an enveloped helical virus
influenzavirus
What are the viral surface proteins on influenza viruses?
Hemmaglutinin (HA) and Neuraminidase (NA)
complex viruses have complex structures. For example many __________ have a polyhedral capsid with a helical tail attached.
bacteriophages
What are the viral surface proteins on HIV? What are their purposes?
gp120- docking glycoprotein
gp41- transmembrane glycoprotein
What specific enzyme is important to HIV?
reverse transcriptase
HIV has more surface molecules from the _____ ______ than molecules by the _______ ________
host cell; virus genome (encoded)
What are some examples of complex viruses?
poxvirus, orthopoxvirus, and bacteriophages
a transmembrane fusion protein. Forms trimers on the virion surface and mediates virus attachment and entry into the host cell
GP
What human proteins are found on the viral membrane of Ebola? What is the purpose of this?
histocompitability (HLA) proteins or other surface receptors, which
in some cases can increase the infectivity of the enveloped viruses.
How do similar viruses differ from each other?
variations on surface proteins
How many subtypes (variations of surface proteins) does influenza A have?
17 different subtypes of HA, 10 of NA
How many subtypes (variations of surface proteins) does poliovirus have?
3 different serotypes
How many subtypes (variations of surface proteins) does rhinovirus have?
100 different serotypes
How are viruses classified?
- nucleic acid
- strategy for replication
- morphology
What do virus families end with? What do genus names end with?
family: -viridae
genus: -virus
What is a viral species?
a group of viruses sharing the same genetic information and ecological niche
What is the HIV cell surface receptor and co-receptor?
CD4 = receptor, CXCR4 = co-receptor
Where do viruses grow and develop?
in living cells
what are the easiest viruses to grow?
bacteriophages
What is the plaque method?
the plaque method mixes bacteriophages with host bacteria and nutrient agar. After several viral multiplication cycles, the bacteria in the area surrounding the original virus are destroyed: the area of lysis is called a plaque.
How do viruses infect?
Viruses have cell surface receptors that recognize human cells and bind to their surface proteins
What is the cell surface molecule for E.coli?
maltoporin (lambB) phage lambda
What is the cell surface molecule for Influenza?
Influenza HA protein binds sialic acid
Different ___ proteins of Influenza A bind different forms of _______ acid
sialic
What does tropism mean?
“tropism” means roughly “what the virus is able to infect
the range of different
species a virus can infect
Host range (or host tropism):
the types of different tissues in an individual a virus can infect
tissue tropism
What determines host range and tissue tropism?
specific host attachment sites: due to differences in surface proteins intracellular factors
intracellular factors: host enzymes and antiviral defenses
Measles first infects immune system cells in the lung via the receptor _______. It then travels via these traveling cells to infect a variety of ________ cells via the receptor ________ 4.
SLAM; epithelial; Nectin
Each plaque originates with a ________ ______ ________; the concentration of viruses is given a ______-_________ _______
single viral particle; plaque-forming units
________ ______ of the immune system deliver ____ to lymph nodes where they infect T cells, which lead to sever decline in immune system function
Dendritic cells (DCs); HIV
Which virus has a broad host range?
influenza viruses, Ebola viruses
Which virus has a small host range?
poliovirus, has a host range of one species
How was Ebola virus introduced to the human population via its natural hosts (fruit bats).
close contact with the blood, secretions, organs or other bodily fluids of infected animals such as chimapanzees, gorillas, fruit bats, monkeys, forest antelope, and porcupines found ill or dead or in the rainforest
The virus surface proteins determine what ______ ________ _________ the virus uses.
cell surface
receptors
What cells the surface receptors are on determines
______ _______, thus the pathology.
tissue tropism
Variation in cell surface receptors determine the _____ _______, that is, what species can be infected.
host range
Variation in virus surface proteins determine the
effectiveness of the _____ _______ ______.
host immune response
Where do intracellular restrictions to viral growth occur?
Restrictions to virus tropism are not just at the surface
of the cell, but can occur at virtually any step of virus
replication, maturation, and release from the cell
Viruses that belong to the Herpesviridae family (genus and species)
Herpesvirus (genus)
Human herpes virus HHV-1, HHV-2, HHV-3
Viruses that belong to the Picornaviridae family (genus and species)
Enterovirus (genus)
Poliovirus
Viruses that belong to Retroviridae (genus and species)
Lentivirus (genus)
Human immunodeficiency virus HIV-1, HIV-2
SS DNA non enveloped virus family
parvovirdae
DS DNA non enveloped viruse family
adenovirus
papovaviridae
DS DNA enveloped virus family
poxviridae
herpesviridae
hepadnaviridae
SS RNA + strand nonenveloped virus family
picornavirdae
caliciviridae
SS RNA + strand enveloped virus family
togaviridae
flaviviridae
coronaviridae
SS RNA - strand virus family
rhabdoviridae
filoviridae
paramyxoviridae
deltaviridae
RNA - strand (multiple) virus family
Orthomyxoviridae
Bunyaviridae
arenaviridae
virus family that makes DNA
retroviridae
DS RNA nonenveloped virus family
Reoviridae
Group I, give examples
I. double-stranded DNA
enveloped poxvirus, herpesvirus
non-enveloped adenovirus, papovavirus
Group II, give examples
II. single-stranded DNA, all non-enveloped parvovirus
Group III, give examples
III. double-stranded RNA, all non-enveloped reovirus
Group IV, give examples
IV. plus or positive (+) stranded RNA
enveloped flavivirus, togavirus, coronavirus
non-enveloped picornavirus, calicivirus
Group V, give examples
V. minus or negative (–) stranded RNA, all
enveloped
one RNA molecule rhabdovirus, filovirus, paramyxovirus
multiple RNA molecules orthomyxo-, bunya-, arenavirus
Group VI, give examples
retroviruses (single-stranded RNA to DNA) enveloped
Group VII, give examples
hepadnaviruses (dsDNA to RNA to dsDNA) enveloped
what does reverse transcriptase do?
RNA to DNA
What is the genome size of: humans (Chr. 1)
3x10^9 bp- human
2.5x10^8 bp- Chr. 1
What is the genome size of: yeast
1x10^7 bp
What is the genome size of: E.coli
4 x 106 bp
What is the genome size of: HIV
9700 nt
Which viral genomes are circular?
a dsDNA virus
Which viral genomes are linear?
+ strand RNA
__________ ______ ______ can’t be translated. It is first copied into ____ strands
- strand viral RNA; +
Which viral genomes are segemented?
- strand RNA
Which proteins are encoded by segments?
flu HA and NA encoded by segments
How are viruses grown in a laboratory? (bacteria, fungi, animals, plants etc.)
Viruses must be grown in living cells
bacteria for bacteriophages
fungi for fungal viruses
animals, animal tissues, or cultured animal cells
for animal viruses
plants or cultured plant cells for plant viruses
Describe the process of growing animal and plant viruses in cell culture
- tissue is treated with enzymes to separate the cells
- cells are suspended in culture medium
- normal cells or primary cells grow in a monolayer across the glass or plastic container. Transformed cells or continuous cell cultures do not grow in a monolayer
Animal viruses may be grown in _______ _______ or in __________ _______
living animals; embryonated eggs
What are some laboratory animal hosts for viruses?
mice rabbits guinea pigs cats rhesus macaque monkeys chimpanzees
How are viruses identified in the lab?
Pathology Culture conditions Serological tests antibodies against viruses in a patient Use antibodies to identify viruses in neutralization tests, viral hemagglutination, and Western blot Nucleic acids PCR sequencing
Describe the lytic cycle of a T-even bacteriophage
- attachment: phage attaches to host cell
- penetration: phage penetrates host cell and injects its DNA
- Biosynthesis: phage DNA directs synthesis of viral components by the host cell
- maturation: viral components are assembled into virions
- host cell lyses, and new virions are released
Phage attaches by tail fibers to host cell
attachment
Phage lysozyme opens cell wall; tail sheath contracts to force tail core and DNA
into cell
penetration
Production of phage DNA and proteins
biosynthesis
Assembly of phage particles
maturation
Phage lysozyme breaks cell wall
release
What is generalized transduction?
the virus carries a
random gene or genes
from a host
to another host
Phage causes lysis and death of host cell
lytic cycle
Prophage DNA incorporated in host DNA
lysogenic cycle
Which cycle can give rise to phage conversion and specialized transduction?
lysogenic cycle
Describe the lysogenic cycle
- phage attaches to the host cell and injects DNA
- The phage DNA circularizes and enters lytic cycle or lysogenic cycle
3A. New phage DNA and proteins are synthesized and assembled into virions
4A. The cell lyses, releasing phage virions
3B. Phage DNA integrates within the bacterial chromosome by recombination, becoming a prophage
4B. Lysogenic bacterium reproduces normally - Occassionally the prophage may excise from the bacterial chromosome by another recombination event, initiating a lytic cycle
The ________ integrates at a specific sequence,
a single spot, in the bacterial chromosome.
prophage
the virus carries a specific gene or set of neighboring genes from a host to another host based on where the \_\_\_\_\_\_\_\_ integrated
prophage
describe the process of specialized transduction
- prophage exists in galactose-using host (containing the gal gene)
- phage genome excises, carrying with it the adjacent gal gene from the host.
- Phage matures and cell lyses, releasing phage carrying gal gene
- Phage infects a cell that cannot ulitize galactose (lacking gal gene)
- Along with the prophage the bacterial gal gene becomes integrated into the new host’s DNA
- Lysogenic cell can now metabolize galactose
does not require lysogeny
as bacterial genome is degraded some is packaged into
phage head
can transduce virtually any gene in chromosome
generalized transduction
requires lysogeny, integration of phage DNA into bacterial
chromosome
prophage excises imperfectly, taking nearby DNA with it
limited to the few genes surrounding integration site
specialized transduction
the bacterium has a new
property due to the presence of the prophage
phage conversion
Provide an example of when a phage conversion by phage infection might be useful for the bacterium?
For example, a disease-causing bacterium may produce a
toxin encoded on a gene in the prophage
Another example: the prophage makes the cell “immune”
to infection by similar phages due to the expression of the
phage repressor protein
what are some differences between bacteriophage and animal virus multiplication?
Bacteriophage: the viral DNA is injected into the host cell. Lyses the cell.
Animal virus: endocytosis or fusion of the virus is how it gets into the cell. Latency is how animal viruses lead to chronic infection.
Describe the process of multiplication of animal viruses
Attachment Penetration Uncoating Biosynthesis Maturation Release by budding
Viruses attach to cell membrane
attachment
by endocytosis or fusion
penetration
by viral or host enzymes
uncoating
Production of nucleic acid and proteins
biosynthesis
Nucleic acid and capsid proteins
assemble
maturation
by budding (enveloped viruses) or rupture
release
How does togavirus enter the cell?
pinocytosis
How does herpes virus enter the cell?
fusion
normally, mammalian cells have what type of polymerases
DNA dependent DNA polymerase
DNA dependent RNA polymerase
A mammalian cell lacks what type of polymerase?
RNA dependent DNA polymerase
RNA dependent RNA polymerase
make DNA from DNA,
it uses the host’s DNA-dependent DNA polymerase
unless it is a cytoplasmic virus, then it uses its own
make RNA from DNA,
it uses the host’s RNA polymerase
unless it’s cytoplasmic
make RNA from RNA,
if it is a + strand virus, it can encode its own polymerase
if it is a – strand virus, it must bring in its own polymerase
make DNA from RNA,
it brings in its own reverse transcriptase
ssDNA: what/where viral nucleic acid synthesis
cellular enzyme, nucleus
dsDNA: what/where viral nucleic acid synthesis (include exceptions)
cellular enzyme, nucleus
except poxvirus: viral enzyme, cytoplasm
except hepadnavirus: cell enzyme, nucleus, then…
− RT converts DNA to RNA to DNA
RNA: what/where viral nucleic acid synthesis (include exceptions)
viral enzyme in cytoplasm
except retrovirus: RT converts DNA to RNA to DNA
−DNA goes to nucleus to integrate
Describe the process of multiplying DNA viruses
- virion attaches to host cell
- virion enters cell, and its DNA is uncoated
- a portion of viral DNA is transcribed, producing mRNA that encodes “early” viral proteins
- viral DNA is replicated, and some viral proteins are made
- Late translation; capsid proteins are synthesized
- virions are mature
- virions are released
a normal mRNA transcript is made from a ___________ and it is a ____ sense strand
dsDNA molecule; + (slide 120)
Describe how a virion is made + strand RNA virus
PICORNAVIRIDAE
- attachment
- entry and uncoating
- strand is transcribed from a viral + genome
- mRNA is transcribed from the - strand - RNA replication by viral RNA dependent RNA polymerase
- translation and synthesis of viral proteins
- maturation and release
Describe the process of making a virion from an antisense strand (- strand) RNA virus (provide example)
RHABDOVIRIDAE
1. attachment
2. entry and uncoating
(The + strand mRNA must first be transcribed from the - viral genome before proteins can be synthesized)
3. RNA replication by viral RNA dependent RNA polymerase
4. 4. translation and synthesis of viral proteins
5. maturation and release
Describe the process of making a virion from a dsRNA virus (provide example)
REOVIRUS
1. attachment
2. entry and uncoating
mRNA is produced inside the capsid and released into the cytoplasm of the host
RNA polymerase initiates production of - strands. The mRNA and - strands form the dsRNA that is incorporated as new viral genome
3. RNA replication by viral RNA dependent RNA polymerase
4. 4. translation and synthesis of viral proteins
5. maturation and release
Describe multiplication of RNA - containing viruses
slide 124
Describe multiplication of retroviruses
slide 125
draw the table (13.4) The Biosynthesis of DNA and RNA viruses compared
slide 126 and 127
has a low error rate
dna synthesis
can “proofread” and the cell has _____-repair mechanisms
dna; dna polymerase
has a high error rate
rna synthesis
cannot proofread
No known _____ repair mechanism is known
RNA; rna polymerase
_____ viruses produce more variants per
replication cycle than _____ viruses
RNA; DNA
An enveloped virus that buds
alphavirus
Describe the steps to budding in an enveloped virus
- viral glycoproteins are pushed on by the viral capsid
- cross section host cytoplasmic membrane starts to come together
- The viral capsid is almost completely enveloped
- the enveloped virus buds off
- an enveloped virion forms
What is a latent viral infection? What is an example of a latent viral infection?
virus remains in asymptomatic host cell for long periods. Cold sores (HSV-1 and 2), shingles (herpesvirus), leukemia (HTLV-1 and 2)
Disease processes occurs over a long period; generally is fatal
persistent viral infections
examples of persistent viral infections
subacute sclerosing panencephalitis (measles virus), cervical cancer (HPV), HIV/AIDS (HIV-1 and 2- lentivirus), Liver cancer (Hepatitis B), Persistent enterovirus infection (Echoviruses), Progressive encephalitis (rubella virus)
transform normal cells into
cancerous cells
activated oncogenes
a process like __________ __________ (involving mRNA)
a process like __________ (involving a provirus)
viral activation of oncogenes not common in humans
generalized transduction; lysogeny
The genetic material of oncogenic viruses becomes
__________ into the host cell’s DNA
integrated
__________ cells have increased growth, loss of
contact inhibition, _______-________ transplant
antigens, and ___ antigens
transformed; tumor-specific; T
What type of viruses are oncogenic viruses usually?
DNA viruses
How are oncogenes activated by provirus?
slide 139
Examples of oncogenic DNA viruses
herpesviruses − EBV papovaviruses − HPV hepadnaviruses − HBV
Examples of oncogenic RNA viruses
retroviruses
− HTLV-1
− HTLV-2
Only about ___% of human cancers are attributable
to viruses.
12
what are the most common virus-associated cancers?
cervical cancer (HPV) liver cancer (hep B and hep C)
− HPV types ___ and ___ cause 70% of cervical cancers
16 and 18
Are virus-associated cancers preventable? How?
Yes, HPV and liver cancer are preventable with vaccination.
Girls and boys, age 11-26, should be vaccinated with a vaccine against four HPV serotypes, including HPV16.
What are some viral proteins that promote cancer?
SV40 a papovavirus
T antigen causes transformation of cells into cancer cells
not viruses naked, infectious RNA require viruses to spread them encodes no proteins only in plants only similar thing in humans is Hepatitis Delta
viriods
What is Chrysanthemum chlorotic mottle viroid?
slide 145
Hep delta encodes one protein, what is it?
the delta antigen (slide 146)
Proteinaceous Infectious particle
Inherited and transmissible by ingestion,
transplant, and surgical instruments
Spongiform encephalopathies: Sheep scrapie,
Creutzfeldt-Jakob disease, GerstmannSträussler-Scheinker
syndrome, fatal familial
insomnia, mad cow disease
resemble viruses epidemiologically,
but are not viruses molecularly.
prions
Describe the process by which prions can be infectious
slide 148
What are the two forms of prion proteins?
a) PrPC
b) PrPSc
How do refolded prion proteins recruit other prion
proteins to refold?
slide 150
class I
dsDNA (enveloped and nonenveloped)
enveloped poxvirus, herpesvirus
non-enveloped adenovirus, papovavirus
class II
ssDNA (all non-enveloped)
Parvovirus
class III
dsRNA, all non-enveloped
Reovirus
class IV
plus strand RNA (enveloped and nonenveloped)
enveloped flavivirus, togavirus, coronavirus
non-enveloped picornavirus, calicivirus
class V
minus strand RNA (all enveloped- one RNA molecule or multiple)
one RNA molecule rhabdovirus, filovirus, paramyxovirus
multiple RNA molecules orthomyxo-, bunya-, arenavirus
class VI
retroviruses (ss RNA to dsDNA)
class VII
hepadnaviruses (dsDNA to RNA to dsDNA)
structure: very large, complex virion
envelope: yes
genome: double-stranded DNA, linear (145-290 kbp)
example: Vaccinia
species: human
tissue: broad, but especially immune system
disease: none, it is a vaccine against Variola (________)
poxviruses; smallpox
structure: medium size, polyhedral virion
envelope: yes
genome: double-stranded DNA, linear (100-200 kbp)
example: HSV Type 1
species: human
tissue: broad: epithelia, fibroblasts, neurons
disease: ________
herpes
structure: large, polyhedral virion
envelope: no
genome: double-stranded DNA, linear (26-45 kbp)
example: ________ _________ Serotype 14
species: human
tissue: respiratory epithelia
disease: acute respiratory disease
Human adenovirus (adenoviruses)
structure: small polyhedral virion
envelope: no
genome: double-stranded DNA, circular (5-8 kbp)
example: ______ _______ ________
species: human
tissue: keratinocytes of skin and mucous membranes
disease: warts, cancers, particularly cervical cancers
(Vaccinate girls and boys!)
HPV (Papovaviruses)
structure: very small icosahedral virion
envelope: no
genome: single-stranded DNA, linear (5 kb)
example: Canine _________
species: dogs, wolves, foxes, cats
tissue: gut, lymphatic system
disease: vomiting, diarrhea and immunosupression
parvovirus
structure: polyhedral virion
envelope: yes
genome: double-stranded RNA
example: _________
species: human
tissue: gastrointestinal tract
disease: severe gastroenteritis in children
rotavirus
reoviruses
structure: polyhedral virion
envelope: yes
genome: plus strand RNA (10-20 kbp)
example: __________
species: human
tissue: broad: respiratory tract, spleen, lymph nodes
disease: “German measles”
rubella (togaviruses)
structure: polyhedral virion
envelope: yes
genome: plus strand RNA (10-11 kbp)
example: ______
species: humans, mosquitos, monkeys
tissue: skin, epithelia, CNS of fetus
disease: fever, rash, birth defects,
Guillain–Barré syndrome
zika; flaviviruses
structure: polyhedral virion
envelope: yes
genome: plus strand RNA (26-32 kbp)
example: _____
species: human, mammals
tissue: lungs, gastrointestinal tract
disease: ________
SARS; SARS; coronavirus
structure: very small, polyhedral virion
envelope: no
genome: plus strand RNA (7.5 kbp)
example: __________
species: human
tissue: intestine, spinal cord
disease: paralysis
poliovirus; picornavirus
structure: small, polyhedral virion
envelope: no
genome: plus strand RNA (7.3-8.3 kbp)
example: _________
species: human
tissue: intestine
disease: gastroenteritis
norovirus (calciviruses)
structure: helical virion
envelope: yes
genome: minus strand RNA (11 kbp)
example: _______
species: human, mammals
tissue: CNS
disease: neurological disease
rabies; rhabdovirus
structure: helical virion
envelope: yes
genome: minus strand RNA (18-19 kbp)
example: ________
species: human, mammals
tissue: broad: fibroblasts, dendritic cells, endothelium,
epithelium
disease: ______________
ebola; ebola hemorrhagic fever; filovirus
structure: helical virion
envelope: yes
genome: minus strand RNA (15-19 kbp)
example: _________
species: human
tissue: respiratory tract, immune system, skin
disease: rash, respiratory illness
measles; paramyxovirus
structure: helical virion
envelope: yes
genome: minus strand RNA, 6-8 segments
example: _________ virus
species: human
tissue: respiratory epithelia
disease: __________, respiratory diseaes
influenza; influenza; orthomyxoviruses
structure: helical virion
envelope: yes
genome: minus strand RNA, segmented
example: __________
species: human, rodents
tissue: broad: blood vessels, kidneys
disease: hemorrhagic fever, renal and pulmonary
syndromes
hantavirus; bunyaviruses
structure: helical virion
envelope: yes
genome: minus strand RNA, segmented
example: _____________
species: human, rodents
tissue: vascular endothelial cells, dendritic cells
disease: acute viral hemorrhagic fever
lassa fever virus; arenaviruses
structure: polyhedral virion
envelope: yes
genome: plus strand RNA* (7-12 kb)
example: ______
species: human
tissue: T-cells, immune system cells
disease: _______
HIV; AIDS; retroviruses
structure: small, polyhedral virion
envelope: yes
genome: double-stranded DNA*, linear (1.7-2 kbp)
example: __________
species: human
tissue: liver
disease: cancer
hep B; hepadnaviruses
structure: no virion
envelope: —
genome: minus strand RNA, circle
example: __________
host: human
tissue: liver
disease: ?
hep delta
Zika viruses are spread by what species?
mosquitoes
