Question

Identify a correct statement about the diseases caused by protozoans.
(a) Trichomoniasis is a sexually transmitted disease caused by a flagellated protist.
(b) Tetranucleate cyst is the infective stage of amoebiasis.
(c) All species of Leishmania use either male or female sand flies as their intermediate hosts.
(d) Tsetse flies act as the primary host for the trypanosomes.

Choose the correct option:

• A. a and b
  
• B. b and c
  
• C. a and c
  
• D. b and d
  

Answer 1

The correct option is A a and b


Trichomoniasis is a sexually transmitted disease caused by the flagellated Trichomonas vaginalis. It is present in the vagina of women. In males, the parasite produces irritation in the urethra. Symptoms are burning sensation, itching, and frothy discharge.

Entamoeba histolytica is responsible for amoebiasis (amoebic dysentery) which is transmitted through contaminated food and water. Tetranucleate cyst is the infective stage. The cyst passes unaltered through the stomach as it is resistant to the action of the gastric juice but is digested by the action of trypsin in the intestine. After excystation in the small intestine, it divides rapidly to produce eight small trophozoites. These trophozoites move to the large intestine where they either invade the host tissue or live as commensals in the lumen of the intestine. They also undergo encystation.

All species of Leishmania use only female sand flies as their intermediate hosts.
Tsetse flies act as an intermediate host for the trypanosomes.