Читать книгу Parasitology - Alan Gunn - Страница 49

The Rhizopoda used to be known as the Sarcomastigophora. It is a small phylum consisting of about 200 species and contains the amoebas. Most rhizopods are free‐living or commensal, but it includes important parasitic species such as Entamoeba histolytica. The name ‘Rhizopoda’ translates as ‘root‐like foot’ and refers to the process by which the cytoplasm flows within the cell to form projections of the body wall called pseudopodia (false feet) that are used for both movement and acquiring food. By sending out pseudopodia, they can surround and entrap small food particles within membrane bound vesicles (food vacuoles) in a process called phagocytosis. In some species, their movement is aided by one or more flagellae. Although amoebas are sometimes described as ‘primitive’, ultrastructural, and molecular studies indicate that this is incorrect.