Which of the following statements correctly describes Balantidium coli?
- A It is the largest protozoan parasite of humans and possesses a kidney-shaped macronucleus ✓
- B It is transmitted through the bite of the tsetse fly
- C Its trophozoite bears four pairs of flagella arising from blepharoplasts
- D It multiplies in erythrocytes producing haemozoin pigment
Correct answer: A. It is the largest protozoan parasite of humans and possesses a kidney-shaped macronucleus
Explanation
Balantidium coli is the only ciliate infecting humans and the largest human protozoan, measuring 50 to 100 micrometres, with cilia covering the body and a characteristic kidney- or sausage-shaped macronucleus. It colonises the colon, causing balantidial dysentery, and pigs are its main reservoir host. Flagellar arrangement describes Giardia, tsetse fly transmission applies to trypanosomes, and erythrocytic multiplication with haemozoin defines Plasmodium.
Reference: Paniker's Textbook of Medical Parasitology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.