Characteristics of Kingdom Protista:

(i) They are unicellular eukaryotic organism i.e., they have membrane bound nucleus and organelles.

(ii) Some of these organism use appendages such as hair like cilia or whip-like flagella for moving around.

(iii) Their mode of nutrition can be autotrophic or heterotrophic.

Examples:Unicellular algae (like Chlamydomonas, Chlorela), diatoms and protozoans like amoeba.