PROTOZOA
Protozoa are chemoheterotrophic organisms that are typically described based on their means of motility.

Amoeboid protozoa (top) are organisms that move toward a stimulus or away from an irritant by extending cytoplasmic projections (known as pseudopodia) in the appropriate direction. As the cytoplasm fills these projections, the amoeba slowly moves in the corresponding direction.

Ciliated protozoa, such as paramecia (bottom right), move by beating thousands of short, hair-like projections (known as cilia) in a coordinated fashion.

Flagellated protozoa, such as trypanosomes (bottom left), move through the environment by whipping a long flagellum back and forth. The flagellum is located at the anterior (front) end of the organism. As the flagellum whips back and forth, the organism is pulled forward.