Coronaviruses Quiz

<p>Reinfection occurs frequently due to brief immunity (A)</p> Signup and view all the answers

<p>Winter (A)</p> Signup and view all the answers

<p>It has a high frequency of mutation and recombination. (D)</p> Signup and view all the answers

<p>Gammaoronivirus (B)</p> Signup and view all the answers

<p>Virus-specific RNA-dependent RNA polymerase. (C)</p> Signup and view all the answers

<p>Into two subfamilies and multiple genera based on several characteristics. (A)</p> Signup and view all the answers

<p>It is widespread in ungulates and linked to diarrheal diseases. (A)</p> Signup and view all the answers

<p>They contribute to the evolution of new virus strains. (B)</p> Signup and view all the answers

<p>Beta and Alpha. (A)</p> Signup and view all the answers

<p>It synthesizes the viral glycoproteins. (D)</p> Signup and view all the answers

<p>Hemagglutinin (A)</p> Signup and view all the answers

<p>It is classified using both hemagglutinin and neuraminidase surface proteins. (A)</p> Signup and view all the answers

<p>9 (C)</p> Signup and view all the answers

<p>Viral entry into host cells (C)</p> Signup and view all the answers

<p>Single-stranded RNA with segments (D)</p> Signup and view all the answers

<p>By combining their hemagglutinin and neuraminidase subtype numbers (B)</p> Signup and view all the answers

<p>Capsid protein (D)</p> Signup and view all the answers

<p>It is antigenically stable. (B)</p> Signup and view all the answers

<p>M2 matrix protein (B)</p> Signup and view all the answers

<p>B/Yamagata and B/Victoria (D)</p> Signup and view all the answers

<p>Hemagglutinin and neuraminidase (B)</p> Signup and view all the answers

<p>Inhibits interferon mRNA production (D)</p> Signup and view all the answers

<p>By binding to neuraminic acid on the cell surface (C)</p> Signup and view all the answers

<p>Provides structural integrity to the virus (D)</p> Signup and view all the answers

<p>It transports protons into the virion (A)</p> Signup and view all the answers

<p>They distinguish between influenza types A, B, and C (B)</p> Signup and view all the answers

<p>Agglutinate red blood cells (A)</p> Signup and view all the answers

<p>70% (A)</p> Signup and view all the answers

<p>It cleaves sialic acid to facilitate viral release (D)</p> Signup and view all the answers

<p>Gradual mutations leading to amino acid changes (D)</p> Signup and view all the answers

<p>IgA (D)</p> Signup and view all the answers

<p>Mediates interaction of nucleocapsid with the envelope (B)</p> Signup and view all the answers

<p>Amantadine (A), Rimantadine (B)</p> Signup and view all the answers

<p>Viral mRNAs primarily move to the cytoplasm for translation (A)</p> Signup and view all the answers

<p>They block the release of the virus from infected cells. (C)</p> Signup and view all the answers

<p>Reassortment of genome RNA segments (D)</p> Signup and view all the answers

<p>The viruses undergo antigenic drift and shift. (B)</p> Signup and view all the answers

<p>In the nucleus to transcribe genome segments (A)</p> Signup and view all the answers

<p>Throat swabs, nasal wash, or nasal aspirates (A)</p> Signup and view all the answers

<p>They diagnose recent infection. (D)</p> Signup and view all the answers

<p>By budding from the outer cell membrane (C)</p> Signup and view all the answers

<p>Contain one or two type A viruses and a type B virus. (D)</p> Signup and view all the answers

Coronaviruses replicate using a virus-specific RNA-dependent RNA polymerase, producing subgenomic mRNAs from a full-length complementary RNA.

Coronaviruses have a high frequency of mutations during replication; this is unusual for RNA viruses with a nonsegmented genome.

Coronaviruses are classified within the Nidovirales order, with subfamilies like Coronavirinae and Torovirinae and genera like Alphacoronavirus, Betacoronavirus, and Gammacoronavirus.

Within the Coronaviridae family, Alphacoronaviruses are one of the genera, along with others such as Betacoronavirus.

Another genus within the Coronaviridae family.

Some coronavirus strains infect humans; two serogroups (229E and OC43) are examples.

Toroviruses are widespread in ungulates, associated with diarrheal disease. They are also part of the Coronaviridae family.

The Coronaviridae family is characterized by particle morphology, RNA replication, genome organization, and nucleotide sequence homology.

HCoV-229E and HCoV-OC43 account for a significant portion (5-30%) of respiratory illnesses, while CoV-NL63 and HCoV-HKU1 are less common (~5% of respiratory samples).

Coronaviruses spread through respiratory droplets, primarily in winter, with roughly a 2-3 year cycle.

The source of SARS-CoV is not elaborated in the provided text.

Approximately half of coronavirus infections do not show noticeable symptoms. While infections are typically limited to the respiratory tract.

Influenza B viruses are classified into two lineages: B/Yamagata and B/Victoria.

Influenza A virus has two surface proteins: Neuraminidase and Hemagglutinin.

M1 matrix protein is located between the internal nucleoprotein and the envelope, providing structural integrity.

M2 matrix protein forms an ion channel, transporting protons into the virion, disrupting the envelope, and releasing the genome RNA.

Influenza viruses possess group-specific and type-specific antigens

The internal ribonucleoprotein complex is the group-specific antigen distinguishing influenza A, B, and C

Hemagglutinin and Neuraminidase are the type-specific antigens located on the surface.

Nonstructural protein NS1 inhibits the production of interferon mRNA, a key defense mechanism of the host cells.

Influenza viruses have a segmented single-stranded RNA genome, a helical nucleocapsid, and an outer lipoprotein envelope with hemagglutinin (HA) and neuraminidase (NA) spikes.

Influenza A viruses are categorized by their hemagglutinin (H) and neuraminidase (N) proteins.

Influenza viruses can change their surface proteins (like HA and NA), making it harder for the immune system to recognize them.

A protein on the influenza virus surface that helps the virus attach to host cells.

A protein on the influenza virus surface that helps the virus release from host cells after infection.

Influenza A subtypes are named using the H and N numbers, like A(H1N1) or A(H3N2).

An enzyme in influenza viruses that helps reproduce the virus's genetic material.

Influenza A viruses are categorized by the properties of their hemagglutinin (H) and neuraminidase (N) surface proteins.

Hemagglutinin (HA) is a protein found on the surface of influenza viruses that binds to sialic acid receptors on host cells, facilitating entry into the cell.

Neuraminidase (NA) is another viral protein that cleaves sialic acid, enabling the release of newly formed viral particles from the infected cell.

Influenza viruses enter host cells through endocytosis, where they are engulfed in a vesicle.

Once inside the cell, the virus's RNA polymerase transcribes its genome into mRNA, which is then translated into viral proteins. New viral RNA genomes are also made.

Antigenic drift refers to small, gradual changes in the influenza virus's proteins, mainly due to point mutations in the genes.

Antigenic shift involves a major change in the virus due to the reassortment of segments of its genome RNA.

New influenza viruses are released from the infected cell by budding from the cell membrane, where the HA and NA proteins are located.

Hemagglutinin (HA) is crucial for the virus to attach to and enter host cells, while neuraminidase (NA) helps the virus release from infected cells and spread. Targeting these proteins with drugs can disrupt the virus's life cycle.

Rapid influenza tests provide results within 24 hours, with around 70% accuracy for infection detection and 90% accuracy for type identification. Viral cultures take 3 to 10 days and involve swabs or aspirates. Blood samples can be tested for antibodies indicating recent infection.

The primary immune response to influenza relies on secretory IgA in the respiratory tract. IgG is also produced but provides less protection. Cytotoxic T cells contribute to protection as well.

Drugs that target influenza viruses include amantadine and rimantadine for influenza A and zanamivir and oseltamivir for both influenza A and B. These neuraminidase inhibitors block the release of new viruses from infected cells.

Inactivated influenza A and B virus vaccines are administered through injection. The vaccine usually contains strains of viruses from the previous winter's outbreaks to provide protection against circulating strains.