All Free Microbiology MCQs with Answers

• A. Measles
• B. Mumps
• C. Rubella
• D. Hepatitis B

Explanation: The hepatitis B vaccine is a subunit or cell-fraction vaccine containing purified hepatitis B surface antigen, produced by recombinant…

• A. Flavi virus
• B. Togaviridae
• C. Reoviridae
• D. Rhabdoviridae

Explanation: Dengue virus is a member of the genus Flavivirus in the family Flaviviridae.

• A. It can be detected during the window period
• B. Free P24 antigen disappears after the appearance of IgM response to it:
• C. Virus load parallel P24 titre
• D. It remains during asymptomatic phase

Explanation: Free p24 antigen is detectable before antibodies appear and usually falls after seroconversion, so it is not continuously present during…

• A. Herpes Simplex
• B. Mumps
• C. Rubella
• D. Papilloma

Explanation: Rubella virus crosses the placenta and can cause congenital rubella syndrome, including cataracts, deafness and cardiac defects.

• A. Chicken pox
• B. Rabies
• C. Small pox
• D. Measles

Explanation: Measles produces both intranuclear and intracytoplasmic inclusion bodies, particularly in giant cells.

• A. Ribonuclease
• B. Reverse transcriptase
• C. DNA polymerase
• D. Restriction endonuclease

Explanation: Retroviruses carry reverse transcriptase, which copies their RNA genome into DNA after entry into the host cell.

• A. Virus
• B. Bacteria
• C. Parasite
• D. Bacteria superadded on virus

Explanation: Dengue haemorrhagic fever is a severe form of dengue virus infection, associated with increased vascular permeability and bleeding.

• A. Protein synthesis
• B. DNA/RNA replication
• C. When virus enters the cell
• D. Uncoating of the virus proteins capsule

Explanation: Interferon induces antiviral proteins that chiefly inhibit viral protein synthesis, especially translation, and also affect viral…

• A. Echo virus
• B. Hepatitis C
• C. HIV
• D. Orthomyxovirus

Explanation: HIV, hepatitis C virus and some enteroviruses can be associated with salivary-gland infection or dysfunction.

• A. Verruca vulgaris
• B. Focal epithelial hyperplasia
• C. Condyloma acuminatum
• D. Keratoacanthoma

Explanation: Verruca vulgaris, focal epithelial hyperplasia and condyloma acuminatum are recognised HPV-associated lesions.

• A. Hepatitis B virus
• B. Hepatitis C virus
• C. Hepatitis E virus
• D. Hepatitis A virus

Explanation: Hepatitis E is especially dangerous during pregnancy and can cause severe, fulminant hepatic failure.

• A. Sialoperoxidase
• B. Secretory IgA
• C. Salivary leukocyte proteinase inhibitor
• D. Histidine rich proteins

Explanation: Salivary leukocyte protease inhibitor, or SLPI, is an innate salivary protein that inhibits HIV infection and helps explain the very low…

• A. Inactive carrier
• B. Healthy carrier
• C. Convalscent carrier
• D. Paradoxical carrier

Explanation: A convalescent carrier has recovered clinically and may have normal laboratory findings but continues to harbour and transmit the…

• A. Saubourd's agar
• B. Rogosa medium
• C. Nonembryonated egg
• D. Embryonated egg

Explanation: Viruses require living cells for replication, so they can be grown in living systems such as embryonated eggs.

• A. Above 600
• B. Between 1000-2000
• C. Below 200
• D. Above 2000

Explanation: In patients with HIV infection, Kaposi sarcoma is strongly associated with advanced immunosuppression, commonly when the CD4 count falls…

• A. Hanta virus pulmonary syndrome is caused by inhalation of rodent urine and faces
• B. Kyanasur forest disease is caused by bite of wild animal
• C. Lyssa virus is transmitted by ticks
• D. None of the above

Explanation: Hantavirus pulmonary syndrome is acquired mainly by inhaling aerosolised particles from infected rodent urine, faeces, or saliva.

• A. Rubella
• B. Rubeola
• C. Herpes simplex
• D. Herpetic ginglvostomatitis

Explanation: German measles is the common name for rubella, a disease caused by rubella virus. Rubeola refers to measles, not German measles.

• A. IgM antibodies in serum
• B. Isolation form stool
• C. Culture from blood
• D. Isolation from bile

Explanation: Acute hepatitis A is best confirmed by detecting anti-HAV IgM in serum, which appears early in infection.

• A. Cowpox
• B. Molluscum contagiosum
• C. Small pox
• D. chicken pox

Explanation: Chickenpox is caused by varicella-zoster virus, a herpesvirus, whereas cowpox, molluscum contagiosum, and smallpox are caused by…

• A. Surface antigen
• B. Surface antibody
• C. Core antigen
• D. Core antibody

Explanation: HBsAg is the main screening marker for current hepatitis B infection, so its detection is used to estimate prevalence.