Protozoa (sg.: protozoan or protozoon; alternative plural: protozoans) are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris.

2025年2月28日 · Protozoan, organism, usually single-celled and heterotrophic (using organic carbon as a source of energy), belonging to any of the major lineages of protists and, like most protists, typically microscopic. All protozoans are eukaryotes and therefore possess a “true,” or membrane-bound, nucleus.

Protozoa are microscopic unicellular eukaryotes that have a relatively complex internal structure and carry out complex metabolic activities. Some protozoa have structures for propulsion or other types of movement. On the basis of light and electron microscopic morphology, the protozoa are currently classified into six phyla.

2017年4月28日 · Organisms known as protozoa include a wide range of organisms, most of which are free-living single-celled eukaryotes. Therefore, protozoa fit into the Domain Eukarya.

2023年8月3日 · Protozoa are unicellular eukaryotic microorganisms having a membrane-bound nucleus and other organelles within their cells. Despite their small size, they are incredibly diverse and exist in various aquatic and terrestrial environments worldwide. More than 50,000 species are known, most of which are free-living organisms.

2022年10月14日 · Protozoa are single-celled organisms that can sometimes cause diseases. Common protozoan diseases include malaria, giardia, and toxoplasmosis. Diagnosing protozoan illness may involve blood tests, stool tests, or biopsies, depending on which protozoa a healthcare provider suspects. Treatment varies based on the cause.

Protozoa are unicellular, eukaryotic, heterotrophic organisms. They are either free-living or parasites. There are around 65000 species of protozoans categorised in different groups. They lack a cell wall.