Protozoa are unicellular organisms.  They consist of :

• A nucleus which is surrounded by a nuclear membrane and contains a karyosome, chromatin granules and nucleoplasm.
• The cytoplasm which contains organelles, vacuoles, glycogen and chromatin bodies

1. Sarcomastigophora which consists of the amoebae and flagellates.

2. Ciliophora which consists of the ciliates

3. Apicomplexa which consists of the coccidia.

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