2025年1月17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, 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 …

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.

Protozoan - Cell Structure, Nutrition, Reproduction: The protozoan cell carries out all of the processes—including feeding, growth, reproduction, excretion, and movement—necessary to sustain and propagate life. The cell is enclosed in a membrane called the plasma membrane.

They live inside the bodies of animals, including humans. Parasitic protozoans can cause disease. A protozoan is just a single cell. But it can do all of the things that organisms with many cells can. A protozoan can eat, grow, reproduce, and get rid of wastes. Most protozoans can move, too.

Protozoan - Evolution and paleontology: Protists were a dominant form of life on Earth 1.5 billion years ago. While protozoans evolved early and have survived to the present day as unicellular organisms, they have undoubtedly undergone considerable evolutionary change.

Protozoan - Unicellular, Microscopic, Diversity: Protozoans range in diameter from a few thousandths of a millimetre to several millimetres. Because the group contains many unrelated or loosely related organisms, enormous diversity in structure and form exists.

This protozoan, which infects red blood cells in birds and reptiles as well as in mammals, occurs worldwide, especially in tropical and temperate zones. The organism is transmitted by the bite of the female Anopheles mosquito.

Protozoan - Adaptations, Nutrition, Movement: For the most part, parasitic protozoans live in a fairly constant environment. Temperature fluctuates very little, or not at all, inside the host, desiccation is not a risk, and food is in constant supply.

protozoan , Any of a group of small (usually microscopic) single-celled protists that are nonfilamentous and heterotrophic (using organic carbon as a source of energy). They are found in most soils, fresh water, and oceans.