Free Virology MCQs with Answers

• A. Acute infection
• B. Carrier state
• C. Prodromal phase
• D. Convalescence

Explanation: A rise in anti-HBc, particularly the IgM component, indicates a recent or acute hepatitis B infection.

• A. Virus
• B. Bacteria
• C. Spirochete
• D. Anaerobe

Explanation: Cytopathic effects are visible structural and functional changes produced in virus-infected host cells, such as cell rounding, lysis, or…

• A. New virus particle arises directly (by division) from preexisting viruses
• B. Fall in to the general size range of 200-3000 angstrom unit
• C. Contain equal proportions of protein, lipo polysaccharide and nucleic acids
• D. Contain DNA but no RNA

Explanation: Viruses commonly measure about 20 to 300 nm, equivalent to roughly 200 to 3000 angstroms.

• A. Chick embryo
• B. Blood agar
• C. Guinea pigs
• D. Cell culture

Explanation: Viruses require living cells for replication, so they can be grown in embryonated eggs, laboratory animals, or cell cultures.

• A. The time lapse between the infection and detection of viral antibodies
• B. The time lapse between the infection and development of AIDS
• C. The time lapse between obtaining the sample and detection of virus in the lab
• D. None of the above

Explanation: The HIV window period is the interval after infection during which antibodies have not yet reached detectable levels.

• A. Red blood cells
• B. Fibroblasts
• C. Helper T lymphocytes (CD4)
• D. Mast cells

Explanation: HIV preferentially infects CD4 helper T lymphocytes through the CD4 receptor and chemokine co-receptors, progressively weakening…

• A. Apthous stomatitis
• B. Tuberculosis
• C. Pneumocystis carinii pneumonia
• D. Herpetic gingivostomatitis

Explanation: Pneumocystis jirovecii pneumonia, formerly called Pneumocystis carinii pneumonia, is the classic AIDS-defining opportunistic infection.

• A. Rheo
• B. Retro
• C. Rhabdo
• D. Flavi

Explanation: HIV is a retrovirus because it carries reverse transcriptase and converts its RNA genome into DNA during replication.

• A. Pox virus
• B. Measles virus
• C. Hepatitis B virus
• D. HIVConsult Online Doctors

Explanation: Measles virus produces both intranuclear and intracytoplasmic inclusion bodies, including cytoplasmic Warthin-Finkeldey-type cells.

• A. Rabies
• B. Poliomyelitis
• C. Influenza
• D. Herpes

Explanation: Rabies vaccination is given after exposure has begun because post-exposure prophylaxis can prevent the virus from reaching the central…

• A. Composed largely proteins without any nucleic acid
• B. Phase in which virus cannot be demonstrated in host cell
• C. Viruses which are genetically deficient
• D. Viral components may be synthesized but maturation & assembling is defective

Explanation: Prions are infectious protein particles composed largely of abnormal protein and contain no DNA or RNA.

• A. Japanese encephalitis
• B. Kuru
• C. Yellow fever
• D. RabiesOrder DNA Kits

Explanation: Pigs act as important amplifying hosts for Japanese encephalitis virus, allowing high levels of viraemia that facilitate transmission by…

• A. Acquires its envelope from nuclear membrane
• B. Acquires its envelope from nucleolar membrane
• C. Acquires its envelope from cytoplasmi membrane
• D. None of the above

Explanation: Herpesviruses acquire their envelope by budding through the inner nuclear membrane, although further processing can occur through cellular…

• A. Enzymes
• B. Protein coat
• C. Polysaccharide
• D. Lipids

Explanation: The viral protein coat contains antigens that stimulate protective antibody and cellular immune responses, forming the basis of many…

• A. Nucleotides
• B. Phospholipids
• C. Scleroproteins
• D. Nucleoproteins

Explanation: Viruses can be crystallized because they behave as organized chemical particles, and their major structural form is nucleoprotein, made of…

• A. Gastrointestinal tract
• B. Nasal mucosa
• C. Lung
• D. Skin

Explanation: Poliovirus usually enters through the mouth and multiplies initially in the oropharyngeal and intestinal mucosa, so the gastrointestinal…

• A. Simple carriers
• B. Late convalescence
• C. High infectivity
• D. Carrier status

Explanation: HBeAg indicates active viral replication and a high level of infectivity in a patient with hepatitis B.

• A. Extracellular infectious virus particle
• B. Smallest virus
• C. A smallest particle similar to virus
• D. None of the above

Explanation: The standard term is virion, meaning a complete infectious virus particle outside a host cell.

• A. Viral interference
• B. Mutation
• C. Supervision
• D. Permutation

Explanation: Viral interference occurs when infection by one virus inhibits the multiplication of another virus, often through interferon production or…

• A. Bunya virus
• B. Reo virus
• C. Calci virus
• D. Rhabdo virus

Explanation: Reoviruses contain a segmented double-stranded RNA genome, whereas bunya, calici and rhabdo viruses have single-stranded RNA genomes.