Described movement in a single cells organisms

Unicellular organisms can move in two distinct ways—movement and locomotion. Movement enables an organism to change its form or shape. ... Unicellular organisms achieve locomotion using cilia and flagella. By creating currents in the surrounding environment, cilia and flagella can move the cell in one direction or another.

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they move through the body till they die of body failure or bacteria

the electromagnetic energy from the sun arrives in the form of visible and invisible light.