Question

Which of the following is a flagellated protozoan?
A. Amoeba
B. Entamoeba
C. Plasmodium
D. Trypanosoma

Answer 1

Hint: A flagellate has generally one or several flagella. The word flagellum means ‘whip’. It is a whip-like structure that protrudes from the cell body generally involved in locomotion.

Complete answer:
An amoeba is a unicellular organism that uses finger-like projections called pseudopodia, for locomotion. Hence, ‘option A’ is incorrect.
Entamoeba belongs to Archamoeba. They are parasitic protozoans found in the intestines of many vertebrates, including humans. They move with the help of pseudopodia. Hence, ‘option B’ is incorrect.
Plasmodium are the parasitic protozoan that belongs to phylum Apicomplexa. One of the species of plasmodium causes malaria in humans. They employ its own actin/myosin based for forward motion. It lacks flagella and cilia. Hence, ‘the option C’ is incorrect.
Trypanosoma belongs to the phylum Sarcomastigophora. They are a group of flagellated protozoa with a life cycle that involves two hosts, an insect vector and a mammalian host.

Hence, the correct answer is option (D).

Additional information:
The majority of species is transmitted by blood-feeding invertebrates and some are spread by direct contact. They are generally found in invertebrates but mainly occupy the bloodstream. They cause many fatal human diseases such as, Sleeping sickness, Chagas disease, etc. Sleeping sickness is caused by Trypanosoma brucei whereas, Chagas disease is caused by Trypanosoma cruzi.

Note: The trypanosomes are transmitted from one host to another through haematophagous insects. There, the parasite multiplies and develops in the gut. The stercorarian trypanosomes develop in the posterior end of the insect gut whereas meta trypanosomes are deposited along with the faeces of the insect vector onto the skin of the host.