Phagotrophy is the mode of ingestion of food materials in many protozoa and in this respect they resemble animals.

Food is captured by means of specialized structures and the protozoa engulf the captured food or suck its contents. In some protozoa, which live symbiotically with other organisms, one may see autotrophy.

A good example of this is the facultative symbiosis between Paramecium bursaria (a protozoan) and Chlorella (photosynthetic microalga);

the symbiosis is called facultative because both the organisms may live independentally in nature.

Paramecium cells harbour large numbers of Chlorella in their cytoplasm, a fact that accounts for their intermittent greenish appearance.

Protozoa belonging to Phyla

A. Mastigophora	B. Rhizopoda	C. Cilophora	D. Sporozoa