A pond organism that is unicellular, contains membrane-bound organelles and possesses a flagellum is a PROTISTA. It is a unicellular kingdom.
The Protista kingdom is composed of eukaryotic single-celled unicellular organisms.
Flagellated protists are microorganisms having a tail-like projection known as flagellum.
The flagellum is a structure used for motion, thereby, in general, flagellated protists are found in moist environments (e.g., ponds, fresh-water, etc).
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