Feb 28, 2025 · The phylum Ciliophora, which includes the ciliated Tetrahymena and Vorticella, contains the greatest number of protozoan species but is the most homogeneous group. The malaria-causing Plasmodium is spread by the bite of a mosquito that injects infective spores (sporozoites) into the bloodstream.

They show wide variation in modes of movement, nutrition, and reproduction. Various classification systems exist to group the protozoans. Commonly known protozoans include dinoflagellates, amoebas, and paramecia (see paramecium).

Feb 4, 2025 · Protozoa, or protozoans, are single-celled, eukaryotic microorganisms. Some protozoa are oval or spherical, others elongated. Still others have different shapes at different stages of the life cycle. Cells can be as small as 1 μm in diameter and as large as 2,000 μm, or 2 mm (visible without magnification).

Feb 28, 2025 · All protozoans possess at least one nucleus, and many species are multinucleate. The genetic material DNA (deoxyribonucleic acid) is contained within the chromosomes of the nucleus. Each nucleus is bounded by two unit membranes possessing pores that permit the passage of molecules between the cytoplasm and the nucleoplasm.

Feb 28, 2025 · Most species of free-living protozoans appear to be obligate aerobes (they cannot survive without oxygen). As in the cells of animals, plants, and fungi, their respiration is based on oxidation (with molecular oxygen, O 2) of the six-carbon glucose molecule, resulting in the formation of carbon dioxide molecules and water.

Feb 28, 2025 · Protists comprise a large and sometimes unwieldy assemblage, and assignments of species to particular taxa change as new genomic approaches, biochemical techniques, and electron microscopy studies provide more details on the affinities of various species.

Feb 4, 2025 · The major groups of microorganisms—namely bacteria, archaea, fungi (yeasts and molds), algae, protozoa, and viruses—are summarized below. Links to the more detailed articles on each of the major groups are provided.

Jan 30, 2025 · Amoeba, any of the microscopic unicellular protozoans of the rhizopodan order Amoebida. The well-known type species, Amoeba proteus, is found on decaying bottom vegetation of freshwater streams and ponds. There are numerous parasitic amoebas. Of six species found in the human alimentary tract,

Feb 28, 2025 · Protozoan - Parasites, Pathogens, Disease: Parasitic protozoans have invaded and successfully established themselves in hosts from practically every animal phylum. The best-studied parasitic species are those of medical and agricultural relevance. The trypanosomes, for example, cause a number of important diseases in humans.

Mar 8, 2025 · The phylum Ciliophora, which includes the ciliated Tetrahymena and Vorticella, contains the greatest number of protozoan species but is the most homogeneous group. The malaria-causing Plasmodium is spread by the bite of a mosquito that injects infective spores (sporozoites) into the bloodstream.