What are protozoans?

Protozoans:

1. They are single-celled heterotrophic eukaryotes.
2. They live as predators or parasites and feed on organic materials such as bacteria, detritus, and other microbes.
3. Amoeboid protozoans, flagellated protozoans, ciliated protozoans, and sporozoans are the four primary groups of protozoans.
4. Many protozoa cause diseases in animals and humans. For example - Plasmodium causes malaria.
5. Examples - Amoeba, Euglena, Trypanosoma.