All Free Microbiology MCQs with Answers

• A. coli
• B. nana
• C. gingivalis
• D. histolytica

Explanation: Entamoeba gingivalis lives in the oral cavity, especially around the gums and teeth, rather than in the large intestine. E.

• A. Cysts are 8 nucleated
• B. Cysts are 4 nucleated
• C. Trophozoites colonise in the colon
• D. The chromatid bodies are stained by iodides

Explanation: A mature Entamoeba histolytica cyst has four nuclei, not eight, so an eight-nucleated cyst is the exception.

• A. Glycogen mass
• B. Chromatid bars
• C. Eccentric nucleus
• D. Refractile nucleus

Explanation: E. histolytica cysts may contain a glycogen mass, chromatoid bars and nuclei with visible nuclear structures.

• A. Dot
• B. Comma
• C. Banana
• D. Sickle

Explanation: Plasmodium falciparum sporozoites are slender and sickle-shaped, which accounts for the option “sickle.” The banana shape is classically…

• A. cats
• B. Dogs
• C. Rats
• D. Cow

Explanation: Cats are the definitive hosts of Toxoplasma gondii, in which the parasite undergoes sexual reproduction and oocysts are shed in faeces.

• A. T. Solium
• B. T. Saginata
• C. Hook worm
• D. A. Lumbricoides

Explanation: Taenia saginata, the beef tapeworm, is generally longer than Taenia solium and the intestinal nematodes listed. Adult T.

• A. Enterobius
• B. Ancylostoma
• C. Ascaris
• D. Necator

Explanation: The threadworm or pinworm is Enterobius vermicularis. Hookworm, Ascaris and Necator are different intestinal nematodes with distinct…

• A. Hook worm
• B. Thread worm
• C. Ascaris
• D. Guinea worm

Explanation: Hookworms cause chronic blood loss by attaching to the intestinal mucosa, making them a major cause of iron-deficiency anaemia in tropical…

• A. Ascariasis
• B. Tapeworm
• C. Hood worm
• D. Ascariasis and tapeworm

Explanation: A tangled mass of Ascaris worms can produce a medusa-lock appearance on contrast X-ray.

• A. Caecum and large intestine
• B. Duodenum
• C. Stomach
• D. Jejunum and Ileum

Explanation: Entamoeba histolytica most often produces amoebic colitis in the caecum and ascending colon, although lesions can extend throughout the…

• A. Giardia lambella
• B. Isopora belli
• C. Balantidium coli
• D. Taenia solium

Explanation: Taenia solium can cause internal autoinfection when eggs released from the adult worm are swallowed and develop into cysticerci, including…

• A. Hemolysis
• B. Malabsorption
• C. Spleen sequestration
• D. Bone marrow depression

Explanation: Falciparum malaria causes anaemia through destruction of infected and uninfected red cells, splenic sequestration, and suppression of…

• A. Trench fever
• B. Relapsing fever
• C. Q fever
• D. Epidemic typhus

Explanation: Lice transmit epidemic typhus, louse-borne relapsing fever, and trench fever.

• A. Sporozoite
• B. Gametocyte
• C. Merozoite
• D. Zygote

Explanation: The mosquito becomes infected when it ingests mature Plasmodium gametocytes from human blood.

• A. Salmonella
• B. Camphylobacter jejuni
• C. histolytica
• D. Y. enterocolitica

Explanation: Humans are the only important reservoir for Entamoeba histolytica, which spreads by ingestion of cysts from contaminated food or water.

• A. Plasmodium vivax
• B. Plasmodium malaria
• C. Plasmodium falciparum
• D. Plasmodium ovaleConsult Online Doctors

Explanation: Crescent or banana-shaped gametocytes are characteristic of Plasmodium falciparum, and its malaria pigment is dark brown to black.

• A. Brain
• B. Liver
• C. Spleen
• D. Lungs

Explanation: The liver is the commonest extraintestinal site because Entamoeba histolytica reaches it through the portal circulation from the…

• A. Solar Keratosis
• B. Malignant pustule
• C. L. Tropica sore
• D. Venereal ulcerTry Prep Courses

Explanation: Delhi boil is the traditional name for the dry cutaneous lesion caused by Leishmania tropica.

• A. Round worm
• B. Whip worm
• C. Tape worm
• D. Seat woman

Explanation: Trichuris trichiura is called the whipworm because its adult has a long, thin anterior end and a thicker posterior end, resembling a whip.

• A. Chocolate agar
• B. NNN
• C. Tellurite
• D. Sabourauds

Explanation: Leishmania is cultured in Novy-MacNeal-Nicolle medium, abbreviated NNN, where the promastigote form can multiply.