MICR 3330 Midterm

What is the most dreadful infectious disease in history?

Smallpox.

What pivotal suggestion did Jeffrey Amherst make in 1763 regarding Native Americans?

He suggested using infected blankets as a form of germ warfare.

Which disease was first recorded by Hippocrates in 412 BC?

Influenza.

What is the primary mode of transmission for poliomyelitis?

Oral-fecal route.

How is Ebola primarily transmitted?

Direct contact with body fluids or contaminated objects.

What does HIV attack in the human body?

The immune system.

What was the outcome of the SARS outbreak in 2002?

It highlighted the importance of early detection and response to viral outbreaks.

What is the cause of most STDs in humans?

Human papillomaviruses.

What is the original host believed to cause Ebola?

Fruit bats or primates.

Which virus is associated with cold sores?

Herpesvirus 1.

What type of viruses are Tobacco mosaic virus and Papaya ringspot virus?

They are notable plant viruses.

Most viruses co-exist with their host through what process?

Genetic mutation and co-adaptation.

What significant discovery regarding viruses was made by Hershey and Chase in 1952?

They proved that DNA is the genetic material in phage T2.

What components do most viruses consist of?

Nucleic acids, proteins, and in some cases, lipids and carbohydrates.

What type of symmetry do rod-shaped viruses exhibit?

Helical symmetry.

What is a virion?

A complete viral particle.

Which structure in viruses is responsible for recognition and attachment to host cells?

Capsid or envelope proteins.

What is the process called when a virus reprograms a host cell to produce viral components?

Biosynthesis.

What traditionally caused the spread of the common cold?

Picornaviruses.

How do naked viruses typically exit the host cell?

By lysis of the infected cell.

What type of viruses primarily undergo budding to acquire their envelope?

Enveloped viruses.

Which virus was the first human virus to be discovered?

Yellow Fever virus.

What role do movement proteins have in plant viruses?

They facilitate the cell-to-cell movement of the virus.

Which vaccine was developed for poliomyelitis?

Inactivated polio vaccine (Salk) and oral polio vaccine (Sabin).

What happens during the eclipse period of the viral replication cycle?

The virus's components are inside the host cell but not yet assembled.

What does the Baltimore classification system focus on in viruses?

The type of genome and the mechanism of mRNA synthesis.

What class do retroviruses fall under in the Baltimore classification?

Class VI.

What are the symptoms of Yellow Fever?

Jaundice, fever, chills, and possibly hemorrhagic fever.

What is the main prevention method against hepatitis C?

There is no vaccine available; treatment with antivirals is used.

How are plant viruses primarily transmitted?

Through insect vectors or mechanical transmission.

What is the role of the poly(A) tail in some viruses?

It aids in the stability and translation of mRNA.

What discovery did Max Theiler make regarding Yellow fever virus?

He developed an attenuated vaccine strain (17-D).

What type of virus is Hepatitis C classified as?

It is a member of Flaviviridae family and is a (+)ssRNA virus.

What is the significance of the research milestone in 1989 related to hepatitis C?

It led to the discovery of the hepatitis C virus through molecular cloning and sequencing.

How do viruses maximize coding capacity?

By using mechanisms such as alternative splicing and polyprotein processing.

What method did Enders, Weller, and Robbins use for polio virus propagation?

Cell culture system.

What structural component is crucial for the assembly of TMV viruses?

Coat protein (CP).

What does the term 'antigenic properties' refer to in viral classification?

The ability of viral proteins to elicit an immune response.

What is a notable consequence of Dengue fever during secondary infections?

Antibody-dependent enhancement leading to more severe outcomes.

What is the purpose of the inclusion bodies formed during viral infection?

They are aggregates of viral components, indicating active viral replication.

Which virus is known as the first animal virus discovered?

Foot-and-mouth disease virus (FMDV).

What role does the M protein play in flavivirus structure?

It is involved in the formation of the virus's envelope.

How does poliovirus infection affect host translation?

It shuts down host mRNA translation, redirecting the machinery for viral protein synthesis.

What feature characterizes icosahedral viruses?

They have a closed, symmetrical structure made from subunits.

What does MOI stand for in virology?

Multiplicity of infection.

What are VLPs in virology?

Virus-like particles used as potential vaccines.

How do viruses like HIV enter host cells?

By binding to specific receptors and undergoing membrane fusion.

What is the historical significance of the Cutter Incident in polio vaccination history?

It highlighted risks associated with vaccines and led to improved safety protocols.

What is one characteristic of naked viruses?

They lack an outer lipid envelope.

What significant characteristic sets apart flaviviruses in terms of transmission?

They are primarily transmitted by arthropod vectors.

How do viruses like TMV achieve cell-to-cell spread in plants?

Through plasmodesmata and movement proteins.

What challenges exist for developing vaccines against Dengue fever?

Antibody-dependent enhancement during secondary infections.

What discovery did Fraenkel-Conrat make regarding TMV?

That RNA is the genetic material and essential for infectivity.

What disease is associated with Epstein-Barr virus?

Infectious mononucleosis.

What is the role of glycoproteins in enveloped viruses?

They facilitate host attachment and entry.

What is an essential feature of RNA viruses?

They typically replicate in the cytoplasm of the host cell.

What does 'quasi-equivalence' mean in the context of viral capsids?

It describes how capsid subunits have similar but not identical bonding relationships.

What are the antiviral strategies used against hepatitis C?

Direct acting antivirals (DAAs) that target key viral enzymes.

What is meant by 'viral tropism'?

The specificity of a virus for a particular host or tissue type.

What is the consequence of genetic reassortment in segmented RNA viruses?

It can lead to the emergence of new viral strains.

How do viruses achieve a high burst size during replication?

By efficiently utilizing the host's cellular machinery to synthesize viral components.

What is the significance of the 5' cap on eukaryotic mRNAs?

It protects mRNA from degradation and is crucial for translation initiation.

What does the one-step growth cycle measure in virology?

The replication kinetics of a virus within a host cell.

What discovery in viral research involved the use of clonal DNA to reconstruct poliovirus?

Reconstruction of poliovirus by assembling synthetic DNA fragments to create infectious clones.

What does a virus require to be classified within a family?

Similar genomic characteristics, structural features, and modes of replication.

What is a typical outcome of chronic hepatitis C infection?

Cirrhosis and potential liver cancer.

What technological approach has advanced HCV treatment significantly?

The development of direct acting antivirals (DAAs).

How do viral infections often induce cytopathic effects in host cells?

By causing structural damage and cell death.

What characteristic is unique to plant viruses like TMV regarding their RNA?

It lacks a poly-A tail but has specific structural motifs for translation.

What type of viruses primarily undergo re-assortment during replication?

Segmented RNA viruses.

Which viral structure is crucial for the attachment process in virus entry?

Attachment proteins on the virus surface.

What were the major public health impacts of smallpox?

It was responsible for millions of deaths historically and led to global vaccination efforts.

What is the basic replication cycle of a virus?

Attachment, entry, biosynthesis, assembly, and egress.

What are the primary hosts for the flavivirus genus?

Birds, rodents, monkeys, and pigs.

How is flavivirus transmitted to humans?

Through bites of infected arthropod vectors, primarily mosquitoes.

Which virus caused the 1918 influenza pandemic?

H1N1 influenza virus.

What role did the International Committee on the Taxonomy of Viruses (ICTV) play?

They regulate the classification and naming of viruses.

What is a significant feature of the coat protein in TMV?

It assembles into a helical structure, forming the virus's protective capsid.

What distinguishes the three classes of viruses in the Baltimore classification?

Their genome type and replication methods.

What discovery is associated with the development of the live attenuated vaccine for measles?

The identification of mutations that reduced virulence.

What class of viruses does the Hepatitis B virus belong to?

dsDNA viruses.

What is the function of the E protein in flaviviruses?

It plays a role in viral entry and fusion with host cells.

What defines a 'permissive cell' for a virus?

A cell that contains the necessary factors for viral replication.

What is the primary challenge in eradicating some viral diseases through vaccines?

The ability of viruses to mutate and evade immune responses.

How do some viruses utilize RNA silencing mechanisms in plants?

To suppress host defenses during infection.

What is the significance of research on transgenic plants in relation to viral resistance?

It demonstrated the potential for genetic engineering to provide protection against virus infections.

What aspect of virology is explored by the use of animal models in research?

Viral pathogenesis and the host immune response.

What is the key concept behind the use of VLPs in vaccines?

They provide immune protection without causing disease.

How do RNA viruses typically achieve replication in host cells?

By using the host cell's machinery for transcription and translation.

What major health outcome resulted from the widespread use of the Salk and Sabin polio vaccines?

Near worldwide eradication of poliomyelitis.

What is the role of the central dogma in virology?

It describes the flow of genetic information from DNA to RNA to protein.

What is a notable characteristic of dsRNA viruses?

They often contain segmented genomes.

What evidence supports that RNA is the genetic material in TMV?

The ability of TMV RNA to infect when combined with coat protein.

How does the immune response to vaccination differ from natural infection?

Vaccination induces a controlled immune response without causing disease.

What are the key components of a virus's structure that help in host attachment?

Capsid and envelope proteins, often arranged as spikes.