Protozoa are classified
by the presence of cilia and flagella and pseudopods or by their non-motility.
This classification method is based on their means of locomotion. These
are flexible membrane extensions of the cells that vary in length and in
structure. The major form of movement exhibited by many protozoans is through
swimming (e.g. sperm cells). They propel themselves at great speeds through their
environment either to transport food particles, expel particulate matter, or
create new developing cells.
