All Free Microbiology MCQs with Answers

• 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.

• A. HBCAg
• B. HBeAg
• C. Anti-HBC
• D. Anti-HBS

Explanation: HBeAg is a marker of active hepatitis B replication and therefore correlates with high infectivity.

• A. HBs Ag
• B. IgM anti - HBc
• C. Anti HBs
• D. None of the above

Explanation: During the hepatitis B window period, HBsAg has disappeared but anti-HBs has not yet appeared; IgM anti-HBc remains the key evidence of…

• A. Give inmunoglobulins for passive immunity
• B. Give ARV
• C. Immediately stitch wound under antibiotic coverage
• D. Immediately wash wound with soap and water

Explanation: A category III dog bite requires immediate washing, rabies vaccine, and rabies immunoglobulin infiltrated around the wound.

• A. Measles virus
• B. Herpes Virus
• C. Papavo virus
• D. Adeno virus

Explanation: Measles virus is an enveloped, single-stranded negative-sense RNA virus.

• A. Immunodeficiency virus
• B. Influenza
• C. Polio virus
• D. Hepatitis virus

Explanation: HIV is a retrovirus because it carries RNA and uses reverse transcriptase to make a DNA copy inside the host cell.

• A. Type 6,12,18
• B. 16,18,31
• C. 6,8,11
• D. 3,10,19

Explanation: HPV types 16, 18 and 31 are high-risk oncogenic types strongly associated with cervical carcinoma.

• A. Interferon production
• B. Toxin production
• C. Lymphocytes production
• D. Neutrophils production

Explanation: Viral infection stimulates interferon production, an important antiviral host response that helps distinguish it from typical bacterial…

• A. RNA -DNA-RNA
• B. RNA-DNA
• C. DNA-RNA
• D. DNA-RNA-DNA

Explanation: A retrovirus follows the sequence RNA to DNA to RNA: reverse transcriptase makes DNA from the viral RNA, and the integrated DNA is later…

• A. 2 weeks
• B. 4 weeks
• C. 9 weeks
• D. 12 weeks

Explanation: HIV seroconversion commonly occurs about 2 to 8 weeks after infection, with many patients becoming antibody-positive around 4 weeks.

• A. ELISA
• B. Western blot
• C. P24 antigen
• D. Lymph node biopsy

Explanation: At three weeks after exposure, the patient may be in acute HIV infection before antibodies become reliably detectable, so p24 antigen is…

• A. HBV
• B. HCV
• C. HDV
• D. HEV

Explanation: HEV infection is usually acute and self-limited and does not commonly progress to chronic hepatitis, except rarely in immunosuppressed…