Here are some examples:
* Bacteria: These are prokaryotic organisms, meaning they lack a nucleus and other membrane-bound organelles.
* Archaea: These are also prokaryotic, but they are distinct from bacteria and often found in extreme environments.
* Protozoa: These are eukaryotic organisms, meaning they have a nucleus and other organelles. They are often single-celled and can be found in a variety of habitats.
* Algae: While some algae are multicellular, many are single-celled, such as diatoms and dinoflagellates.
Let me know if you'd like to know more about any of these organisms!
