When speaking of prokaryotes, we generally refer to a cellular structure without a nucleus in which the genetic material is dispersed in the cytoplasm. Organisms made up of this type of cell are included in the empire prokaryotaa top-level taxonomic rank that is divided into the domains Archea Y Bacterium.

All prokaryotic organisms are unicellular but many can form large colonies and aggregate communities. One of the few exceptions are myxobacteria (order Myxococcales), a group of bacteria that have the largest known bacterial genome, composed of about 12.5 million nucleotides, and that have stages in their life cycle that some authors consider multicellular. There are also authors who describe some species of magnetotactic bacteria as necessarily multicellular.

On the other hand, eukaryotic organisms are made up of cells that have a nucleus in which the genetic material is stored. These organisms are included in the empire eukaryota and it is currently believed that they come from prokaryotic organisms through an evolutionary process of endosymbiosis.

within eukaryotes we find four great kingdoms: animalia (animals), plant (floors), fungi (fungi) and protist (protozoa). All are multicellular organisms except protozoa and yeast. (a type of mushroom).

Protozoa are a highly paraphyletic taxonomic group of eukaryotic organisms. they are mostly unicellular, although they also contain some multicellular organisms, for example the so-called brown algae. Among the best known unicellular protozoa we could mention the paramecia, the plasmodium or the amoebas.

Yeasts are defined as unicellular microscopic fungi. Strictly speaking, “true” yeasts are found only in the division Ascomycota, which are unicellular throughout their life cycle. But the term yeast has been extended, especially in microbiology, to all fungi in which the unicellular phase predominates in the life cycle, for example the division Basidiomycota.

Therefore, it can be affirmed that there are unicellular eukaryotic organisms and that they abound in nature.