Morphology

Abstract

Aside from the special cases mentioned in the preceding chapter, the individual protozoan cell represents a whole organism which must perform all the functions necessary for the survival of the species. Certain functions are often carried out by special cell areas which form a structural entity and are called organelles in analogy to the organs of the Metazoa. Thus, the individual cells of the Protozoa generally reach a higher degree of differentiation than metazoan tissue cells which are only required to fulfill a part of the functions in the entire mechanism of the organism. Like all animal and plant cells, the Protozoa also consist of cytoplasm, separated from the surrounding medium by a special cell envelope, and the cell nucleus.