General characters of Phylum Protozoa:
They are parasites or free-living.
- They have flagella for locomotion.
- Their body is covered by a cuticle or pellicle.
- Freshwater forms have a contractile vacuole.
- These are acellular organisms with Protoplasmic organisation.
- Division of labour is at the level of cell organelles.
- These undergo asexual reproduction either by binary fission or by multiple fission.
- Some undergo sexual reproduction by conjugation or autogamy or endomixis.
- All fresh water and many parasitic Protozoans undergo encystment for dispersal and perennation.
- Nutrition is either holozoic or saprozoic or parasitic.
