The simplest form of protist based on its simple cell structure and ability to change shape in response to external disturbance would be amoeba.
Amoeba is a unicellular organism that belongs to the division of living organisms known as protists.
Amoeba can be found in freshwater environments such as ponds, moist soils, lakes, etc. The cell contains important organelles such as the nucleus, contractile vacuole, etc.
A typical amoeba cell has no definitive shape but changes according to different environmental stimuli.
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