eukaryotes
Bacteria *facepalm*
protists
A small single-celled organism that does not contain nuclei is known as a prokaryote. Prokaryotes include bacteria and archaea, which are simpler in structure compared to eukaryotic cells that have a nucleus. These organisms have genetic material that is not enclosed within a membrane-bound nucleus.
There are many single celled organisms (unicellular).Life on Earth is separated into two main divisions: the prokaryotes and the eukaryotes. Both of these contain single celled organism.The prokaryotes are the eubateria and the archaebacteria. Both of these kingdoms only contain single celled organisms. Prokaryotic organisms have no nucleus and have no membrane bound organelles.Within the eukaryotes the kingdoms of amoebozoa, fungi and plantae contain single celled organisms. In all cases these organisms have a nucleus and membrane bound organelles.The amoebozoa kingdom contains such things as the amoeba and slime molds. Fungi comprise the molds, mushrooms, toadstools and other similar organisms. Plantae are the plants.
protists
The kingdom Protista contain all single celled organisms. Examples are: protozoans (animal-like single celled organisms) and algae (plant-like single celled organisms).
Sinle celled organisms are called "microorganisms". Bacteria are microorganisms with no nucleus. Protists are single celled organisms that are like animals because they have a nucleus. Examples: amoeba, paramecium
Prokaryotes are single-celled organisms that lack a nucleus and membrane-bound organelles, while eukaryotes are organisms with cells that have a nucleus and membrane-bound organelles. Eukaryotes include both single-celled (e.g., protists) and multicellular organisms (e.g., plants, animals).
Prokaryotes don't have a nucleus - their DNA is floating free in the cell cytoplasm. in other words they lack a Nucleus
Single-celled organisms can vary widely in their cellular structures. Prokaryotes, such as bacteria, do not have a nucleolus or a defined nucleus; their genetic material is located in a nucleoid region. In contrast, some eukaryotic single-celled organisms, like protists or yeast, do have a nucleus and may also contain a nucleolus, which is involved in ribosome production. Therefore, whether a single-celled organism has a nucleolus depends on its classification as prokaryotic or eukaryotic.
Single celled organisms with nuclei belong in the domain eukarya and the kingdom Protista or fungi. A paramecium is an example of a protist.
Prokaryotes are single-celled organisms without a nucleus or membrane-bound organelles, while eukaryotes are more complex organisms with a nucleus and membrane-bound organelles. Eukaryotes can be single-celled or multicellular, while prokaryotes are always single-celled.