Virology Exam 1 (chapters 1-5)

What are the 5 categories in order that the ICTV uses to assign taxonomy to viruses?

-Order (-virales) -Family (-viridae) -Subfamily (-virinae) -Genus (-virus) -Species

What are the 5 reasons that virus particles are formed? (my acronym is PERFS because it's easier to remember than PRSFE but use what works for you)

-Protection -Economy -Recognition -Fidelity -Self-assembly

There are seven classes of viruses based on nucleic acid (replication of genome). What are all seven of them?

-dsDNA -ssDNA -dsRNA -(+)ssRNA -(-)ssRNA -RNA reverse-transcribing viruses (retrovirus) -DNA reverse-transcribing viruses (retrovirus)

What are the three steps of Eukaryotic translation?

-initiation -elongation -termination

What are three new ways that vaccine delivery is being considered?

-nasal sprays -skin patches -time-release pills

What are six different recombinant DNA methods used for new generation vaccines today?

-recombinant subunits -peptides -live vectors -reassortant viruses -naked viruses -edible plants

What are the five major entry/exit points for viruses?

-respiratory tract -GI tract -Sexually -conjunctiva -placental

When talking about order of viruses, what is the term used?

-virales

When talking about family of viruses, what is the term used?

-viridae

When talking about the subfamily of viruses, what is the term used?

-virinae

When talking about genus of viruses, what is the term used?

-virus

At what micron level will no known viruses pass through?

0.1 microns

What are the key steps of the viral replication cycle? Hint: A PUG

1. attachment (absorption) 2. penetration (entry) 3. uncoating (disassembly and localization) 4. genome replication and gene expression

Generally speaking, what percent of virus particles are able to infect a host cell?

1/100

How many HIV virus particles are needed to successfully cause an infection?

100

Most viruses are around

100 nm or below

How many vertices does the icosahedral viral shape have?

12

Viral infections are linked to approximately what percent of all cancers?

12%

30 unknown viruses were found in 2015 in

15,000 year old glaciers

There were three major outbreaks of polio. What years did these outbreaks occur?

1916, 1940s, and 1950s

Transmission electron microscope was invented in

1931

Hantavirus had a major outbreak in what two years?

1993 (U.S. four corners region) and 2012 (Yosemite Park)

How many faces does the icosahedral viral shape have?

20

One person with measles could theoretically infect how many people?

20

The 1918 influenza pandemic killed around how many people?

20-50 million people

Measles was eliminated in what year, only to rise up again because of obnoxious antivaxers?

2000

When did MERS-CoV arise?

2012-present

Even though there are millions of viruses, there are only approximately ________ disease-causing viruses.

220

What is the range of genome lengths in ssRNA viruses?

2300-31000

In what direction is the genetic information COPIED/READ?

3'-5'

What is the range of giruses genomes?

300-1200 kb

How many different beta defensins are there?

31

What percent of the population seems to be resistant to HIV-1?

5%

What is the direction nucleic acid synthesis ALWAYS goes in?

5' to 3'

Ribosome initiation occurs at the __________ in the _________ of the cell

5'm7Gppp, cytoplasm

How many different alpha defensins are there?

6

How many proteins does polio encode?

7

MHC class I must be restricted to a size of about

8-9 residues

IgG makes up what percentage of antibodies?

80%

Giruses can encode up to how many proteins?

900

Around what percentage of viruses are smaller than bacteria?

99%

It takes an incredible amount of _________ to maintain immune systems.

ATP

After viral replication, cells lyse due to a lack of three things. What are those three things?

ATP, +RNA, and nucleotides

What is the start codon for all mammals?

AUG (methionine)

What are the protein receptors on Covid?

Ace2

Herpes (HSV-1) had the most genetic diversity 150,000-200,000 years ago somewhere in

Africa

Who is the major contributing arsehole that published fraudulent reports linking MMR (Measles, Mumps, Rubella) vaccine to autism, which subsequently lowered confidence in vaccination?

Andrew Wakefield

What lymphocyte is born and matured in the bone marrow?

B cells

A virus that protects the metazoan host from invading bacteria in our guts are called

BAM Velcro (Bacteriophage Adhering to host Mucus)

Why has polio not significantly changed genetically in the last 100 years?

Because it is already very stable. Any mutations would make it less stable

Why aren't there any drugs that interfere with the endocytic pathways and exocytic pathways?

Because nothing good or bad would go in or out and every cell would obviously die

15,000 years ago, herpes was able to cross from Russia to North America by the use of the

Bering Strait

Today there is a mimivirus that caused a pneumonia outbreak in Bradford, England in 1992. What did the scientists mistake it as to begin with due to its large size?

Bradford coccus

Individuals with ________ have more favorable prognosis during antiretroviral therapy.

CCR2

Individuals with defective _________ are resistant to HIV-1 compared to those with wildtype alleles.

CCR5

T helper cells are usually associated with

CD4 and MHC II

Cytotoxic T-lymphocytes are usually associated with

CD8 and MHC I

What two viruses have the ability to target the kidneys?

CMV and hantavirus

Scientists were able to recreate the 1918 influenza by going to ____________ and take samples from some frozen soldiers.

Canada

SARS emerged where and when?

China 2002-2003

Viral genes that have closely related homologs in cellular organisms (especially hosts of given viruses) describes what class out of the 5 classes of viral genes?

Class 1

Viral genes that are conserved within a major group of viruses that have distantly related cellular homologs describes what class of viral genes?

Class 2

Virus-specific genes that have no detectable cellular homologs (ORFans) describes what class of viral genes?

Class 3

Virus-specific genes that are conserved in a broad group of viruses but have no detectable homologs in cellular life forms describe what class of viral genes?

Class 4

Genes shared by many diverse groups of viruses with only distantly related homologs in cellular organisms, also called viral hallmark genes, describe what class of viral genes?

Class 5

What is a point of viral entry moves materials from the TGN to endosomes, lysosomes, and plant vacuoles?

Clathrin-coated pits/vacuoles

What viruses has the ability to target the heart?

Coxsackie B

This virus protects mice from the bacterial infections Listeria monocytogenes and Yersinia pestis.

Cytomegalovirus

DNA viruses rarely mutate because ______________ proofreads for mistakes.

DNA polymerase

What synthesizes dsDNA?

DNA polymerases

What two processes happen within the host nucleus?

DNA replication and RNA transcription

What type of viruses appears to possibly share a common ancestor?

DNA viruses

The Hershey-Chase experiment determined that

DNA, not protein, is the hereditary material of viruses

ssDNA viruses have to convert their DNA because the host cell doesn't contain any __________________ _________________ _____________ to convert ssDNA to mRNA

DNA-dependent RNA polymerase

What term describes positively charges, small peptides (around 29-42 amino acids long), that have hydrophilic and hydrophobic properties?

Defensins

What model addresses interactions among host, agent, and environment?

Disease triangle method

Who was the doctor who died trying to bring attention to SARS-CoV in 2003?

Dr. Urbani

This virus is essential for the development of wings in rosy-apple aphids, which allows them to colonize new plants when food is less abundant and plants are crowded.

Dysaphis plantaginea densovirus

What disease is caused by foreign bodies in the eye?

EKC (Epidemic keratoconjunctivitis)

What virus devastated areas in West Africa from 2014-2016?

Ebola

Who is most acknowledged for their work with cowpox vaccination?

Edward Jenner

Who developed the cell culture techniques known as one-step growth in the 1940s?

Enders, Weller, and Robbins

Koalas that harbor this virus are protected from lymphomas and leukemia

Endogenous koala virus (KoRV)

What term describes the small, accessible portion of an antigen that can be recognized?

Epitopes

Who was the most famous adult who suffered from polio?

FDR

True or False: Humans are NOT the only real host to polio.

False

True or False: antibodies can go inside of our cells.

False

True or False: there are vaccines available to prevent HIV.

False

What is another name for virus attachment proteins?

Glycoprotein spikes

The scientists who discovered the 30 unknown viruses in glaciers in 2015 found them in the

Guliya ice cap

What virus is a great example of viral envelopes formed by interactions between viral proteins?

HIV

What virus is an example of a cancer-causing virus as it causes cervical cancer?

HPV

Herpes simplex virus 1 has the abbreviation of

HSV-1

What vaccine is considered new generation as it only has recombinant subunits from viral surface proteins?

Hep B

What is one example of ss/dsDNA viruses that use an RNA intermediate?

Hepatitis B (hepadnavirus)

One example where a virus needs a helper virus is

Hepatitis D (It needs Hep B to survive, even though Hep B doesn't need Hep D)

Who were the scientists responsible for discovering concerning activations of innate immunity, along with discovering toll receptors and toll-like receptors (TLRs)?

Hoffmann and Beutler

What project has characterized the microbial communities found at several different sites on the human body: nasal passages, oral cavity, skin, gastrointestinal tract, and urogenital tract?

Human Microbiome Project (HMP)

Who is charged with developing a universal taxonomic scheme to name and classify viruses?

ICTV (International Committee on Taxonomy of Viruses)

What type of IFN is known as IFN-gamma, which possess antiviral activity?

IFN Type III

What type of IFN binds to a receptor complex called human IFN-alphabeta receptor (IFN-alphabetaR)?

IFN type I

What type of IFN is there only one of in humans (IFN-y) which upregulates immune response?

IFN type II

What in our bodies causes phagocytosis by WBC's and prevents pathogens from adhering to mucous membranes?

IgA antibodies

What antibody is the most stable, as it can last for around 20 days?

IgG

What in our bodies is most prevalent in serum, provides naturally acquired passive immunity, neutralizes bacterial toxins, participates in complement fixation and enhances phagocytosis?

IgG antibodies

During the primary response, the first antibodies to be produced are the

IgM

What antibodies are pentamers, consist of 5-10% of serum antibodies, and are found in the blood, lymph, and on B cells?

IgM

Dane particle is a ss/dsDNA virus is associated with:

Infectious HBV

What virus is a sneaky thief, since they steal our mRNA caps by using an enzyme that cuts them off in the nucleus?

Influenza

What and when was the first influenza pandemic in the 21st century?

Influenza A (H1N1) in 2009

Viruses take advantage of the cells, but they especially take advantage of the _____________ step of Eukaryotic translation.

Initiation

Who discovered IFN, also known as the magic bullet?

Isaacs and Lindenmann

Germ theory of disease developed in 1880s is also known as

Koch's postulates (Robert Koch)

The ribosomal scanning model is called __________, since it is named after Marilyn___________

Kozak

The theory that viruses are derived from the last universal common ancestor is called (hint: it's an acronym)

LUCA

What is another name for skin cells?

Langerhan's cells

What is the term for a set of proteins found on the plasma membranes of cells that help display antigens to T cells?

MHC

What term describes molecules that are expressed on the cell surface of all nucleated cells and present peptide fragments derived from intracellular proteins? These peptides are normally derived from the cell's own 'house-keeping' proteins (cytosolic) but in a virally infected cell, peptides derived from viral proteins may also be presented.

MHC class I

What molecules are normally found only on professional antigen-presenting cells such as dendritic cells, mononuclear phagocytes, some endothelial cells, thymic epithelial cells, and B cells? Hint: These cells are important in initiating immune responses and their antigens presented are derived from extracellular proteins, not cytosolic proteins.

MHC class II

A common sequence in a peptide antigen that binds to an MHC molecule is called a

MOTIF

The process where DNA from a group of species is collected from an environmental sample and sequenced is called

Metagenomics

Discovery of new viruses is increasing rapidly because of

Metagenomics, next generation sequencing, and bioinformatics

For the H1N1 virus (Influenza A), what country was the epicenter?

Mexico

What does MERS-CoV stand for?

Middle East Respiratory Syndrome Coronavirus

MHC class I has binding energy from

N, C termini

Are there any naked helical viruses?

NO

Can viruses produce ATP?

NO

What type of cells scan all cells in the search for disease indicators like declined MHC expression and/or surface antigens so that they can kill those cells?

Natural killer (NK) cells

Is the exact origin of MERS-CoV known?

No

Can viruses be fossilized?

No, they can be frozen

Does HIV lyse cells?

No, they pinch themselves off

What is the term that describes a form of RNA that does not encode for proteins, but rather has functions of its own?

Non-coding RNAs

What trigger innate immunity responses in by body defense cells?

PAMPs

Neurotropic viruses can access three different neural entries. One way they can do it is by entering through the nerves that connect the _________ of the body to the _________.

PNS, CNS

The theory that viruses fell from outer space in the form of meteors from Mars is called the

Panspermia hypothesis

What deposits eggs and polydnavirus particles into caterpillars?

Parasitoid wasps

What type of viruses can't enter the cell via protein receptors, but rather by injury/opening in/on the host?

Plant viruses

What can be used to purify a clonal population of a virus?

Plaque assay

What virus is extremely stable and has no envelope?

Polio

What is the largest dsDNA virus to infect mammalian cells?

Pox virus

What is the only DNA virus able to replicate in the cytoplasm?

Pox virus

Influenza has multiple

RNA fragments

What type of viruses can sometimes make their own copies, cleave themselves, and have enzymatic activity?

RNA viruses

IFNs work by stopping and degrading _________ synthesis and temporarily stops ________ synthesis, which directly interferes with viral replication.

RNA, protein

What is the term that describes a vaccine made by combining antigens from several viruses or from several strains of the same virus.

Reassortant vaccines

According to Dr. Roner, what virus causes the worst smelling diarrhea?

Rotavirus

What major virus caused an outbreak in Europe from 2011-2013?

Schmallenberg virus

What virus has rosette patterns?

Simian Virus

The 1918 influenza pandemic was also called the

Spanish flu

B cells need confirmation from ____ ________ to make sure that they need to continue making antibodies.

T cells

What lymphocyte is born in bone marrow but matures in the thymus gland?

T cells

What works with CD4 receptors on their cell-surface membranes, which bind to antigens on antigen-presenting cells and produce interleukins, a type of cytokine.

T helper cells

HIV victims often have constant infections because of the decreased immunity caused by depletion of ________________________ from HIV-1.

T helper lymphocytes

MHC class I molecules are transported to the ER by

TAP1/2

What was the movement that began in 1938 to raise money for polio treatment and research?

The March of Dimes

Why can't viruses enter the outer layer of skin cells?

The cells are dead (no receptors to bind to)

For different viruses, think about T=X. What does X represent?

The self-assembly complexity (lower the number, lower the complexity.

The Chamberland porcelain ultrafilters were used to isolate the very first virus called

Tobacco mosaic virus (TMV)

True or False: All mammalian helical (-)RNA viruses have an envelope?

True

True or False: B cells can only make one type of antibodies at one time.

True

True or False: There are spherical and helical viruses that are enveloped.

True

True or False: Viral genomes consist of only one type of nucleic acid (RNA/DNA).

True

What are three end termination codons?

UAA, UGA, UAG

What is an international watchdog and relief organization for children?

UNICEF

What term describes the oncolytic viruses used to kill cancer cells?

Virotherapy

What is a common deficiency in developing countries?

Vitamin A deficiency (VAD)

Places where viruses were first isolated was in Uganda in the ________ _________ region in 1937.

West Nile

What virus has a cage network?

West Nile

Do giruses have more than one membrane?

Yes

What virus causes birth defects in babies where the mother had been infected before the embryo was conceived? Hint: if already well into the 2nd or 3rd trimester, it will not cause birth defects as it can't pass through the placenta.

Zika virus

What is another name for the attachment phase of a virus?

absorption

What does AIDS stand for?

acquired immune deficiency syndrome

A hurdle a virus must overcome is that viruses must move around __________, which is responsible for holding membranes and everything together.

actin

What part of the cell assists with virus movement and assembly?

actin cortex

What affects every stage of viral replication, so much so that viruses have to disrupt them to create stress fibers?

actin remodeling

What type of infection comes on rapidly and has severe, but short-lived, effects?

acute infection

HIV was so harsh on humans because the virus was not ____________ to us, but rather they were used to their original host. With time, HIV has now become less harmful, and the people have become more resilient.

adapted

IFNs also work by upregulating expression of __________ __________ response genes.

adaptive immune

What viruses are associated with eye infections and colds/respiratory infections?

adenovirus

What term is used to describe drugs typically used in conjunction with vaccines and other drugs to increase efficacy?

adjuvant

Hand sanitizer can kill viruses because viruses have space. They are not

air-proof

What are the two types of defensins?

alpha and beta

There are three types of IFNs (I, II, and III) that are differentiated based on _________ _________ composition.

amino acid

Amino acids common to many peptides tether the peptide to structural features of the MHC molecule called

anchor residues

MHC class I and class II has what that fills specific pockets?

anchor residues

This is a cryptic plant virus that paralyzes and kills aphids on wheat as a survival strategy for wheat and the virus.

aphid lethal paralysis virus (ALPV)

What term describes programmed cell death (PCD)?

apoptosis

What influence ecology and diversity, evolution, and health of all aquatic organisms?

aquatic viromes

Viruses that infect what are prone to change shape during heating? Hint: They have many shapes, including lemon like shapes.

archaea

At what temperature does the human body have a cap on?

around 106

What is the term when a vaccine is composed of a weakened form of the pathogen that is generally unable to cause disease?

attenuated

MHC class II receive binding energy from the

backbone

The complement system is mainly used to lyse ___________ and possibly destroy the envelopes of ___________.

bacteria, viruses

Do lymph nodes generally swell more with viral infections or bacterial infections?

bacterial infections

What can be used as a weapon against bacterial superbugs, as well as serving as a treatment of bacterial biofilms?

bacteriophage therapy

What is the probable animal reservoir for ebola?

bats

In 2007, a major norovirus outbreak occurred in a Wisconsin restaurant because their well didn't reach the

bedrock

The application of mathematics and computer science to store, retrieve, and analyze biological data is called

bioinformatics

The Schmallenberg virus caused disease in livestock spread via

biting midges

Neurotropic viruses are capable of CNS entry because they can cross the semipermeable

blood-brain barrier

Viruses that can cross the placenta are typically

bloodborne viruses

Lymph supplies lymphocytes to the

bloodstream

Neurotropic viruses can access three different neural entries. One way they can do it is by entering through the ________________ during viremia.

bloodstream

IgG are monomers that circulate in the _______________, _____________, and __________.

bloodstream, tissues, placenta

What is another name for phagocytic cells?

body defense cells

Viruses can be transmitted via ___________ ___________ or ____________ transplants.

bone marrow, organ

Viruses infecting the _________ are shed through other organs, which are the primary sites of replication.

brain

The WHO and United Nations Mission for Ebola Response had a 70-70-60 plan. What is this plan? This plan ensures that 70% of ____________ are done safely, 70% of suspected cases are _____________, within 60 days.

burials, isolated

What is a major source of zoonosis potential?

bushmeat

Schmallenberg Virus caused congenital defects in

calves and lamb

MERS-CoV spreads from

camel to person

What is the reservoir for MERS-CoV?

camels (Dromedary)

Do capsomers have to be the same, or can they be different?

can be different

Retroviruses are important as many of them cause

cancer

What are two types of mRNA translation?

cap-dependent and cap-independent

Most viruses have a difficult time getting their mRNA ___________

capped

What protects the nucleic acid genome of viruses from nucleases?

capsid

Every virus must have a ____________ made up of _____________.

capsid, capsomers

The third step of viral replication involves the removal or degradation of the ____________ to release the ____________ into the host cell.

capsid, genome

All viruses have genes that code for

capsids

What are three examples of systems that can cause systemic infections?

cardiac, PNS/CNS, lymphatic

What are the main proteases that carry out apoptosis?

caspases

What are three virus uptake and vacuoles at the cell surface?

caveola, clatherin-coated pit, and pinocytic vesicle

What essentially packages the cell materials into little sections during apoptosis?

cell blebbing

What part of the cell acts as receptors that bind to viral surface proteins?

cell surface structures

Viruses use several different mechanisms to evade elimination by the host. One way is blocking ___________ __________ like apoptosis, complement, and IFN pathways.

cellular pathways

Often times, the cell thinks that the invading virus is actually a __________ ___________ that has a ticket to go straight to the nucleus.

cellular protein

What part of the cell also facilitates transport and serves as a source of membranes, however is not as important as others listed here?

cellular vacuoles

What induces the migration of leukocytes?

chemokines

The majority of individuals in need of vaccines are ____________ located in _____________ countries.

children, impoverished

What type of pattern of disease is associated with persistency over extended periods of time with continuous progression? Ex: syphilis

chronic infection

Human alpha and beta defensins work directly with viruses by _________ and _________ receptors.

clumping, blocking

Virophages are small, dsDNA viral phages that require the

coinfection of another virus

What system consists of more than 30 different serum- and membrane-bound glycoproteins that act in sequence (one activates another)?

complement system

When thinking about (-)ssRNA, we can think about it being the

complimentary strand to mRNA

Genome length in viruses varies greatly depending on

composition

Lots of factors contribute to virus survival, including ____________ of the virus.

composition

Less lethal viruses cause ____________ _____________ during pregnancy.

congenital malformations

What term describes the mucous membrane that lines the eyelid and covers the front of the sclera to serve as the first line of defense for the eyes?

conjunctiva

Peptides bound to a particular type of MHC class I molecule have ___________ __________ of amino acids.

conserved patterns

Viral and cell DNA have the same

control region

What type of proteins may accompany the viral genome inside the capsid?

core proteins

What term describes the cell surface protein that enhances the sensitivity of an antigen receptor?

coreceptors

Lymph nodes swell to

create antibodies

What does corona mean in coronavirus?

crown

What is another name for the norovirus?

cruise ship virus

What term describes substances that produce low temperatures or prevent excessive temperature elevation?

cryogens

The rats infected with SV40 developed tumors, which scared scientists. However, SV40 can't replicate in humans, which means no tumors. SV40 forms a lifelong association with the humans, even though no disease is caused. SV40 is what type of virus in humans?

cryptic

Persistent viruses that form lifelong associations with host WITHOUT causing disease are called

cryptic viruses

During self-assembly, polymer chains are folded into what packed shape?

cubes

There are some disadvantages of traditional vaccines. One is that not all viruses can be _____________.

cultivated

Viruses use several different mechanisms to evade elimination by the host. One way is inactivating _____________ signals.

cytokine

What is the term that describes a potentially fatal immune reaction caused by highly elevated levels of various cytokines?

cytokine storm

What part of the cell is the source of enzymes and has components for viral synthesis?

cytoplasm

What term describes the network of protein filaments or polymers?

cytoskeleton

What causes the direct destruction of antigen carrying cells?

cytotoxic T-lymphocytes

Hantavirus is isolated from what resevoir?

deer mice

Giruses often _____________ virophages to the host.

deliver

What cells are present in tissues that are in contact with the environment?

dendritic cells

Kissing, sex, touching, sneezing, breastmilk, coughing in someone's face, and animal bites are all examples of

direct transmission

Civil War soldiers were more likely to die from what than battle?

disease

Viruses have also been named after what ___________ the virus caused.

disease (ex: hepatitis)

How was SARS transmitted?

droplets

Giruses have a core with

dsDNA

Which virus genome type usually uses the cell's nucleus for DNA replication and RNA transcription?

dsDNA

ssDNA viruses must convert their linear ssDNA to

dsDNA form

What type of nucleic acid only exists in viruses?

dsRNA

RNA in viral genomes can be four different types. What are the four different types?

dsRNA, ss(+)RNA, ss(-)RNA, and retrovirus

Scientists use what piece of machinery to view the inside and outside of viruses?

electron microscope

Particles get IN the cell via

endocytic pathways

What term describes the route for moving materials from outside the cell (and from the membrane surface of the cell) to compartments, such as endosomes and lysosomes, located within the cell interior?

endocytosis (endocytic pathways)

What part of the cell is responsible for transport, protein folding, glycosylation, protein processing, as well as being a secondary source of membranes for viruses?

endoplasmic reticulum

What part of the cell is a digestive vacuole that facilitates the acidification of uptake vacuole, which activates viral synthesis?

endosome

What term describes the genetic element that can replicate either as part of the bacterial chromosome or independently of it?

endosome

MHC class II is generated in

endosomes/lysosomes

Cells that lyse not because of lytic enzymes lyse because a lack of ATP, +RNA, and nucleotides. Essentially, a lack of __________ to keep the cell going causes it to lyse and die.

energy

Viruses that are generally transmitted via fecal-oral route are called

enteric viruses

What virus sometimes causes conjunctivitis (pink eye)?

enterovirus type 70

Shedding (exiting) of human viruses usually occurs at the __________ point.

entry

Human alpha and beta defensins inhibit ______ and _______ viruses.

enveloped, naked

Bacteriophages sometimes produce ____________ that lyse bacteria cells or produce something toxic to the cell.

enzymes/proteins

When ssDNA viruses switch to dsDNA, the dsDNA enters the nucleus to form an

episome

When B cells encounter a pathogen, they activate any B cell produces antibodies that can bind to the __________ of the virus.

epitopes

Antibodies from our bodies and vaccines have to cover

every receptor on a virus

Viruses can enter hosts in two different, but equally direct ways. What are the two ways?

existing entry points or bites

Particles get OUT of the cell via

exocytic pathways

Coding segments of eukaryotic DNA are called

exons

True or False: viruses can replicate WITHOUT a host cell.

false

Do DNA reverse-transcribing viruses mutate slower or faster than other DNA viruses?

faster

The immune system changes during pregnancy to become less sensitive so that the _________ won't be recognized as foreign tissue and be attacked by IgG antibodies that can cross the placenta.

fetus

What is another term used to describe helical viral shape?

filamentous

Back in the day, viruses were called

filtratable agents

The Kozak consensus sequence is NNGCC(A/G)CCAUG(G). Which base is the only one that can't change, as it would decrease translation frequency? Word it like first A, second G, like that for which one you think has to stay to have 100% translation frequency.

first G

What describes the structural model of the plasma membrane where molecules are free to move sideways within a lipid bilayer?

fluid mosaic model

T cells recognize cells that contain _________ _________ (virally infected cells, tumor cells, foreign tissue grafts).

foreign antigens

What animal was "vaccinated" with rabies in Texas via the animal's favorite food?

foxes

NK cells, monocytes, macrophages, and neutrophils express receptors for the ___________ ___________ (Fc) region of antibodies.

fragment crystalliable

The first three letters in the Kozak consensus sequence (excluding NN) is important. The strength of those three letters (GCC, or GXX where X are other bases) determines the

frequency of binding

What describes the delivery of functional copies of dysfunctional genes via retroviruses and adenoviruses?

gene therapy

What is the word for protein-coding sequences in the human genome?

genes

Viral immunity has a ___________ component.

genetic

What term describes variants that occur in the chromosomes of 1% or more of the general population?

genetic polymorphisms

Modern research now likes to classify viruses based on

genetics and morphology

The type of ________ determines the first step after uncoating (whether its translation, transcription, or RNA replication).

genome

What drug is an example of a hormone therapy that is also an immunosuppressive agent?

glucocorticoids

What part of the cell facilitates protein glycosylation and is yet another source of membranes for virus use?

golgi apparatus

Viral particles take advantage of the ________ ________ to get out of the host cell.

golgi stack

What are cytotoxic enzymes that initiate apoptosis?

granzymes (proteases)

Macropinocytosis is ___________ ___________ induced, and is an _________ __________ form of pinocytosis.

growth-factor, actin-dependent

All resulting new or emerging infectious disease caused by hantavirus is called

hantavirus pulmonary syndrome (HPS)

Ebola spread rapidly through

healthcare and travel

The 1918 influenza outbreak was an exception to the idea that elderly and newborns are most affected as ____________ people were exhibiting more devastating symptoms than unhealthy people.

healthy

Only a few viruses infect these two organs, what are they?

heart and kidneys

The balance of cryogens and pyrogens determines the _________ and _________ of the fever response to immune challenges.

height, duration

Which viral shape can be squished/crushed?

helical

Is the Dengue virus icosahedral or helical/spherical?

helical/spherical

T cells later become

helper cells

What is one family of viruses that are DNA reverse-transcribing?

hepadnaviridae

What type of viruses like to attack the liver?

hepatitis viruses

What is an example of an acute infection followed by persistent latent infection? (essentially comes quick and then chills in the person for the rest of their life with maybe some flare-ups)

herpes

Scientists are able to learn about viruses by tracking

herpes and human migration

What describes a gene sequence that is similar to a gene sequence in the cellular (host) genome?

homolog

Patients undergoing certain ___________ therapies are at an increased risk for viral infections.

hormone

What term describes the range of cells that can act as a host for a virus?

host range

What was the main mode of transmission for polio, even though it was unknown at the time?

human feces

Bacteriophages were first isolated in sources such as

human sewage

Viruses tend to generate anywhere from a couple ___________ to a couple ____________ virus particles in a host cell.

hundred, thousand

The theory that suggests that pores in hydrothermal vents provided templates for cells is called the

hydrothermal origin hypothesis

What rare condition is the result from the complexing of IgG or IgM antibodies capable of activating the complement system?

hypocomplementemia

Which viral shape can not be changed?

icosahedral

Most viruses fall into two viral shape categories. What are the two categories?

icosahedral and helical

Viruses use several different mechanisms to evade elimination by the host. One way is inactivating _____________ cells.

immune

Astronauts have to be careful when leaving earth because any pathogens that join them could start an outbreak, and because their ________ ________ is suppressed in space.

immune system

Transplant patients taking immunosuppressive drugs, HIV-infected individuals, and cancer patients receiving intensive therapy are all considered

immunocompromised hosts

There are some disadvantages of traditional vaccines. One is that the vaccine may not be adequately ____________ or ___________.

inactivated, attenuated

Are giruses being discovered increasingly or decreasingly in frequency?

increasingly

SARS was a super-spreading due to having a longer __________ ______ than other viral diseases, which allowed people to travel without symptoms.

incubation period

blood, fomites, food, aerosols (coughing in general vicinity), insects, and water are all examples of

indirect transmission

"uncapped" mRNAs usually are

ineffecient

What is the term that describes the amount of virus particles needed to cause an infection?

infectious dose

IFN, apoptosis, phagocytes, dendritic cells, natural killer cells, and the complement system are all part of the

innate immunity (first line of defense)

What protects us against any pathogen, regardless of the species or type of microbe?

innate immunity (nonspecific)

Deficiencies and malnutrition interfere with __________ and _________ immunity.

innate, adaptive

What proteins penetrate the hydrophobic interior of the lipid bilayer?

integral

Plasma membranes have ___________ and ___________ proteins within the phospholipid bilayer.

integral, peripheral

Viruses do not possess __________ activity

integrase

What enzyme is often responsible for integrating viral DNA into the host cell's DNA?

integrase

What are antiviral proteins that can act as cytokines?

interferons (IFNs)

What does IRES stand for?

internal ribosome entry site

Noncoding segments of nucleic acid that lie between coding sequences are called

introns

ORFs are created when _________ are removed from RNA

introns

Viruses tend to only have exons, not exons and ________

introns

Traditional vaccines contain either ___________ or inactivated viruses, or ____________, attenuated viruses.

killed, live

What does Kb stand for when discussing viruses?

kilobases

What is a virus survival tactic, allowing for intergenerational virus transmission?

latency (dormant state)

There is evidence that what type of viruses form immunity against bacterial pathogens?

latent viruses

What is the term when viruses are transmitted because of a physician, tools, or therapy?

latrogenic induction

Smaller DNA viruses can only replicate first on the ________ _________ before replicating on the next strand.

leading strand

When 40s ribosomal subunit bypasses the first AUG to initiate translation farther downstream, ________ _________ occurs.

leaky scanning

MHC class II can have any

length

What is the enzyme that connects two fragments of DNA to make a single fragment?

ligase

Enveloped viruses steal what from the host cell?

lipid bilayer (cell membrane)

What term describes concentrated infections that don't spread to other parts of the body?

localized viral infections

Memory B cells patrol the

lymphatic system

What system is composed of a network of vessels, ducts, nodes, and organs that provides defense against infections?

lymphatic system

When thinking about (+)ssRNA, we can think about it as being

mRNA

What term describes a process through which the Ebola virion is swiftly engulfed by the cell membrane of the host cell?

macropinocytosis

What term describes flat spots on the skin?

macules

Viruses can attack the skin and cause rashes as four different things. What are they?

macules, papules, vesicles, or pustules

What does MHC stand for?

major histocompatibility complex

What is the most contagious viral disease to humans?

measles

What term describes the first line of defense as it traps viruses by mucus and phagocytes in mucosal tract?

mechanical immunity

Complement activation ends in the formation of a ____________ _______ ______ (MAC).

membrane attack complex

Which cells are most involved in a secondary response?

memory B cells

Viruses require _______________ ___________ cells, so they must enter through breaks in the skin.

metabolically active cells

What is the term used to describe the total of all microbiota that live on or inside the human body?

microbiome

What part of the cell traffic viruses through endosomes, as well as ferry capsids to the nucleus?

microtubule organizing center

What are three examples of protein filaments?

microtubules, actin and intermediate filaments

DNA of different HSV-1 strains (herpes) helps researchers to study

migration patterns

What are the other two names for Giruses, or giant DNA-containing viruses?

mimi and mamavirus

Viruses use several different mechanisms to evade elimination by the host. One way is latency and _________ _________.

molecular mimicry

Viruses have also been named after using electron microscopes, as they can see the

morphology

RNA viruses tend to be more unstable due to no proofreading polymerase. This often results in

mutations

What type of vaccine consist of plasmid DNAs that have been manipulated to contain a gene encoding a specific viral antigen?

naked DNA vaccines

Age, hormones, diet, dual infections, genes, and species resistance are all a part of the physiological factors and barriers of our

natural defenses

What type of viruses infect the nervous system?

neurotropic viruses

Viruses use several different mechanisms to evade elimination by the host. One way is to synthesize excessive soluble viral antigens that bind all of the host's ___________ ____________.

neutralizing antibodies

When discussing age and disease, ____________ and ____________ are usually the most vulnerable.

newborns, elderly

Entire genomes sequenced using multiple parallel reactions to analyze short segments of DNA and compare the results to known sequences is known as

next generation sequencing

Do lungs have a clear exit where they can secrete fluids?

no

Do naked viruses have attachment proteins?

no

Do the giruses their fibrils to attach?

no

Lymphocytes congregate in the lymph ________ and exit through the outgoing lymph ___________.

nodes, vessels

Are most mammalian viruses lytic or nonlytic?

nonlytic

Is Hantavirus contagious human-to-human or not?

not

Is most viral RNA spliced or not spliced?

not spliced

Microtubules, actin, and intermediate filaments are all attached to the

nuclear envelope

What part of the cell mediates entry and exit inside the cell, as well as being a secondary source of membranes for viruses?

nuclear membrane

Even though viruses virtually have no trouble self-assembling, they do have trouble obtaining/creating

nucleic acids

What term describes the capsid composed of capsomers and the nucleic acid together?

nucleocapsid

All DNA viruses must enter the

nucleus

What part of the cell do viruses carry out DNA replication, RNA splicing, and find mRNA caps, DNA polymerases, and RNA polymerases?

nucleus

The example of parasitoid wasps and polydnaviruses (a provirus) is an example of

obligatory mutualism

Neurotropic viruses can access three different neural entries. One way they can do it is by entering through the _____________ nerves.

olfactory

Toll-like receptors (TLRs)

on host cells attach to pathogen-associated molecular patterns (PAMPs)

What viruses are used to kill cancer cells as they can only replicate in tumor cells?

oncolytic viruses

All studies/experiments that receive government funding must be free after

one year

How many DNA reverse-transcribing viruses infect humans?

one, hepatitis

What type of experiments are used as a way to study a single replication cycle, while also providing information about events at each step of the infection cycle?

one-step growth

What is the hallmark of HIV infection?

opportunistic infections

Viruses that enter through the GI tract enter through the

oral-fecal route (lovely)

Bacteriophages are able to stay _____________ the bacteria cell, while eukaryotic viruses have to go _______________ the cell or they will be noticed.

outside, inside

Penetration ability by a virus is also affected by

pH in or dependency

What term describes firm, raised areas such as pimples and the eruptions seen in some stages of chickenpox and syphilis?

papules

Polydnavirus expresses only wasp genes that

paralyze caterpillar

Using recombinant DNA methods for vaccines is usually safer because it only uses _________ ___ _________ than the whole virus.

parts of virus

Newborns often get __________ _______ from their mothers.

passive immunity

Body defense cells contain pattern-recognition receptors (PRRs) that recognize ____________ _______ __________ __________ (PAMPs).

pathogen-associated molecular patterns

Body defense cells contain ________ __________ __________ (PRRs) that recognize pathogen-associated molecular patterns (PAMPs).

pattern-recognition receptors

Viruses are also named after the _________ who discovered them.

people (ex: Epstein-Barr is herpes but named after him)

What protein pokes holes in pathogens to allow toxins to enter?

perforin

Once activated, natural killer cells release pore-forming proteins called

perforins, granzymes (preteases), and chemokines

What term describes the disease transmission that involves the infection of a fetus or newborn before birth or at the time of delivery via the mother?

perinatal

What proteins are not embedded in the lipid bilayer, but rather are appendages loosely bound to the surface of the membrane?

peripheral

What engulf and ingest viruses and bacteria within our bodies?

phagocytes

What term describes a type of endocytosis in which a cell engulfs large particles or whole cells?

phagocytosis (cell eating)

The plasma membrane is composed of a

phospholipid bilayer

The ICTV database classifies viruses based on what properties?

physical and chemical

What term describes a type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes?

pinocytosis (cell drinking)

B cells later become

plasma cells

What part of the cell allows viral entry to the cell by fusion, viral exit from cells, and is the source of membranes?

plasma membrane

When B cells encounter viruses, the activated B cells differentiate into clones of __________ cells and _________ cells to express the correct antibody.

plasma, memory

Mimiviruses can sometimes cause cases of

pneumonia

One example of a secondary infection being lethal is that the primary Influenza A virus may be the initial infection, but often times the potentially lethal secondary ______________ swoops in.

pneumonia

Side chains of anchor residues bind into ____________ in the MHC molecules.

pockets

What is one example of a naked virus?

polio

Parasitoid wasps deposit eggs and what virus into caterpillars?

polydnavirus

Particles that consist of multiple circles of double-stranded DNA encased in capsid proteins and an envelope are called

polydnavirus

What describes a large protein expressed from a single gene and subsequently cleaved to form several individual proteins?

polyprotein

What is the class of viruses that constitute a replicating lineage and occupy a particular ecological niche. Hint; they have many, but not all properties in common.

polythetic class

Which sense (positive or negative) can be immediately translated using host cell protein synthesis machinary?

positive

What term describes disease that is transferred through breastmilk or other after birth means?

postnatal transmission

What term describes the covalent and generally enzymatic modification of proteins during or after protein synthesis?

posttranslational modifications

What type of viruses essentially "dissolve" people and are fairly lethal?

pox viruses

What is the term when a virus first enters the bloodstream?

primary viremia

What is the enzyme that joins RNA nucleotides to make the primer using the parental DNA strand as a template?

primase

What are two other cellular proteins besides polymerase involved in DNA replication?

primases and ligase

Once these two protein factors bind to their target DNA regulatory sequence elements gene expression (transcription) can begin. What are the two protein factors?

promoters and enhancers

MHC class I molecules are generated by

proteasome (cytosol)

Enveloped viruses steal part of the host cell membrane for their

protective envelope

B cells recognize whole _________ __________.

protein antigens

Bacteria have the ability to shutdown __________ _________

protein synthesis

Viruses don't have their own

protein translation

Humans and other eukaryotic organisms can't shut down protein synthesis because we have higher

protein turnover

To avoid virus-host cell mRNA competition, viruses evolved ways to produce abundant amounts of their own _________ to combat expression of numerous cellular genes from _________ ________

protein, host cell

One out of the two most critical events during viral genome replication and gene expression is the production of virus structural _______ and _________.

proteins, enzymes

What are four cell surface receptors that viruses can bind to?

proteins, glycoproteins, carbohydrates, and glycolipids

A viral genome that is permanently inserted into a host genome is called

provirus

The H1N1 (Influenza A) outbreak was a result of various

public health initiatives

What term describes pus-filled sacs such as those seen in acne primarily?

pustules

What term describes fever producing substances?

pyrogens

how much mucus is produced a day?

quarts of it apparently

Scientists in 1930 were able to isolate what virus by severing the spinal cords of little adorable bunnies?

rabies

What is an example of a recombinant live-vector vaccine?

rabies

What virus replicates in muscle tissue surrounding a bite that transmitted the virus?

rabies

Viruses use several different mechanisms to evade elimination by the host. One way is ___________ ___________, which allows them to escape neutralizing antibodies and the Tc cell responses.

rapid mutation

Is latrogenic induction rare or common?

rare

Some viruses have genes that code for

receptor-binding proteins

What describes the movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in? Hint: it also enables a cell to acquire bulk quantities of specific substances.

receptor-mediated endocytosis

Some species have resistance to some diseases because they lack __________ for viruses to bind

receptors

There is a new generation of vaccines that are made using what methods?

recombinant DNA

Humans are exposed to enteric viruses through multiple ways. One way is through sewage-polluted _______________ and ____________ water.

recreational, drinking

Tethering amino acids in MHC molecules need not be identical, but it must be

related

Virus particles tend to not show up on a plaque assay during the _________ stage.

replication

What three steps are all localized processes in eukaryotic host cells?

replication, transcription, and translation

HIV is a

retrovirus

What describes an RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome?

retrovirus

There are some disadvantages of traditional vaccines. One is that sometimes there is a ____________ of attenuated viruses like Polio.

reversion

What is the term when the ribosome shifts into another reading frame and then continues translating the mRNA into protein in that new frame?

ribosomal frameshifting

What part of the cell is located on the rough ER in the cytoplasm that is responsible for translation of mRNA?

ribosomes

A hurdle that viruses must overcome has to do with __________ and viral _______ compatibility.

ribosomes, mRNA

Recombinant Live-Vector Vaccines have genes coding for surface proteins of pathogenic viruses inserted into

safe viruses

Viral infections of the respiratory tract tend to lower the body's resistance to ___________ __________

secondary infections

Viruses with ________ _________ are emerging pathogens. SARS, MERS, Ebola, Hantaviruses, and arenaviruses are all examples of this.

segmented genomes

dsRNA viruses are always ___________ and have _______ or more fragments.

segmented, 3

What does SARS stand for?

severe acute respiratory syndrome

There are some disadvantages of traditional vaccines. One is that there are ________ ________ limitations.

shelf-life

Early discovery of viruses were named based on the _________ of the infectious agent.

size

What is an organ that fits in the mechanical immunity genre?

skin

Deficiencies and malnutrition interfere with the integrity of ___________ and __________ membranes.

skin, mucous

Viruses enter hosts through ________ or ________ membranes.

skin, mucous

Where are common areas where you would find dendritic cells?

skin, mucous membranes, lining of nose and lungs, and GI tract.

What describes a viral infection in which, following an acute stage, the virus persists and eventually brings about symptoms that kill the host?

slow infection

Using a scraping instrument, scientists in 1930 were able to inoculate orphans with scabs to create a "vaccine" from what virus?

smallpox

What virus is illegal to work with unless permitted by the government(s)?

smallpox

What virus is one of the largest, and has a brick shape?

smallpox

What virus really only exists in a few labs around the world nowadays?

smallpox

In 1930, what two "vaccines" were available?

smallpox and rabies

MHC class II bind in

specialized vesicles (MIIC)

What signals direct incorporation of viral genomes into virions?

specific packaging signals

Pox viruses have the ability to _______ their own RNA

splice

A hurdle that viruses must overcome has to do with alternative/differential ______________

splicing

As a possible part of RNA transcription, what else takes place in the host nucleus (besides DNA replication)?

splicing

There are three outcomes of severe infections while pregnant? What are they?

spontaneous abortion, stillbirth, and neonatal death

DNA in viral genomes can only be two types. What are the two types?

ssDNA and dsDNA

The defective CCR5 gene contains a premature _______ ________ that shortens protein-preventing binding of HIV-1.

stop codon

What term describes the different isolates of the same virus, or in other words, the same virus but different phenotypic changes?

strain

The body's response to one infection may increase ______________ to a secondary infection.

susceptibility

What term describes the sets of physical signs and symptoms that occur together?

syndromes

Viruses use the host's protein synthesis machinery because viral genomes do not have the capacity to contain all genes necessary to

synthesize proteins

What is the term when an infection spreads throughout the host (basically it is not localized)?

systemic infection

What is the nongenetic material at the end of chromosomes to protect against gene loss in eukaryotic cells?

telomeres

Lots of factors contribute to virus survival, including _________, ___________, and __________.

temp, humidity, and pH

Most pathogens are _________ sensitive.

temperature

What is the term when there is a drug induced birth defect (congenital malformation?

teratogenic effect

What membrane protein inhibits the release of viruses from the cell surface?

tetherin

What organ will kill most viruses that enter it?

the stomach

What describes a type of PRR that enables the innate system to correctly identify pathogens?

toll receptors

Mammalian viruses don't produce any __________ ___________ that hurt the host, unlike some bacteriophages.

toxic enzymes/proteins

There are some disadvantages of traditional vaccines. One is that not all viruses, like HIV and Hep C, can be prevented with

traditional vaccines

What three contributing factors increase zoonoses viruses?

trafficking of bushmeat, bioterrorism, and climate change

dsDNA viruses (besides pox) must go to the nucleus to either ______________ ___________ or use _______________.

transcribe mRNA, polymerase

Viruses can be transmitted through ____________ and blood products.

transfusion

What is the process that enables the ribosome to pass through the termination codon in mRNA and continue translation to the next STOP codon in the same reading frame?

translational readthrough

What term describes the movement of a pathogen from an infected woman to her fetus across the placenta?

transplacental

What does TAP stand for?

transporter of antigenic peptide

Measles was brought into the United States because unvaccinated U.S. residents contracted the disease from

traveling to affected regions

Viruses can ____________ and/or _____________ PCD.

trigger, counteract

What types of cells can contain displayed surface antigens?

tumor or virally infected cells

Does HIV have one or two protein binding receptors?

two

Humans are exposed to enteric viruses through multiple ways. One way is the consumption of __________________ _______________ grown in contaminated waters.

undercooked shellfish

Are RNA viruses often related or unrelated genetically?

unrelated

There are some disadvantages of traditional vaccines. One is that it there may be low yields of __________ _________.

vaccine strains

Your innate immune system usually is able to fight off minor infections, which is the reason why there are not ___________ for every disease.

vaccines

What is the term that describes a virus that differs from the original wild-type strain?

variant

Sometimes viruses are named after acronyms based on what __________ transmits them.

vector (ex: arboviruses come from an anthropod vector)

What are created via herpes on the lips? They are also known as cold sores?

vesicles

A hurdle a virus must overcome is that RNA-dependent RNA polymerase are incapable of replicating

viral genomes

Formation of viral envelopes by budding is driven by interactions between

viral proteins

Leaky scanning allows multiple _______ ________ to be synthesized from a single __________.

viral proteins, mRNA

dsRNA viruses carry their own RNA-dependent RNA polymerase within

virion particle

Subviral agents within other big viruses are called

virophages

The second most critical event during viral genome replication and gene expression is the replication of the __________ ___________.

virus genome (dsDNA, ssDNA, dsRNA, ssRNA)

Almost every major advancement in microbiology is because of

viruses

Are viruses or bacteria more stable in water?

viruses

Lots of factors contribute to virus survival, including whether viruses present in human and animal ____________.

wastes

Humans are exposed to enteric viruses through multiple ways. One way is through food crops that are grown using ________________ for irrigation or ___________ __________ as fertilizer.

wastewater, human sewage

SARS spread rapidly in healthcare settings among

workers, patients, and visitors

Does COVID have the ability to spread to other tissue?

yes

Does the virus, for lack of better words, control the ratio of protein synthesis during translational readthrough?

yes

What is the most common form of transmission?

zoonoses

What term describes the transmission of viruses from animal to human?

zoonoses