Updated by: Arabinda Naik
1. Kingdom: Protista.
2. They are known as acellular or non-cellular organism. A protozoan body consists of only mass of protoplasm, so they are called acellular or non-cellular animals.
3. Habitat: mostly aquatic, either free living or parasitic or commensal
4. Grade of organization: protoplasmic grade of organization. Single cell performs all the vital activities thus the single cell acts like a whole body.
5. Body of protozoa is either naked or covered by a pellicle.
6. Locomotion: Locomotory organ are pseudopodia (false foot) or cilia or absent. 7. Nutrition: Nutrition are holophytic (like plant) or holozoic (like animal) or saprophytic or parasitic.
8. Digestion: digestion is intracellular, occurs in food vacuoles.
9. Respiration: through the body surface.
10. Osmoregulation: Contractile vacuoles helps in osmoregulation.
11. Reproduction: Asexually reproduction is through binary fission or budding. Sexual reproduction is by syngamy conjugation.
Examples: Amoeba, Entamoeba, Giardia, Euglena. Trypanosoma, Plasmodium. Monocystis, Paramecium, Vorticella. Balantidium