Which organism is categorized as a protozoan parasite?

Which organism is categorized as a protozoan parasite?

• A. Heartworm
• B. Tapeworm
• C. Coccidia
• D. Flea

Answer: (C)

Protozoan parasites are single-celled eukaryotes that often invade host tissues, sometimes living inside intestinal cells. Coccidia are a group of intracellular protozoan parasites that infect the intestinal lining and form oocysts shed in feces. This intracellular, single-celled nature is what defines them as protozoa. Heartworm is a nematode (a multicellular worm), tapeworms are cestodes (flat, segmented worms), and fleas are arthropods (insects) that live on the outside of the host. These are not protozoans, which is why coccidia is the correct choice.

Protozoan parasites are single-celled eukaryotes that often invade host tissues, sometimes living inside intestinal cells. Coccidia are a group of intracellular protozoan parasites that infect the intestinal lining and form oocysts shed in feces. This intracellular, single-celled nature is what defines them as protozoa.

Heartworm is a nematode (a multicellular worm), tapeworms are cestodes (flat, segmented worms), and fleas are arthropods (insects) that live on the outside of the host. These are not protozoans, which is why coccidia is the correct choice.