* Bacteria: These are tiny prokaryotic organisms found everywhere.
* Archaea: Similar to bacteria, these are also prokaryotic and often found in extreme environments.
* Protozoa: These are eukaryotic, single-celled organisms that can be found in water, soil, and even inside other organisms. Examples include amoeba, paramecium, and Euglena.
* Yeast: These are single-celled fungi that are used in baking and brewing.
* Algae: While some algae are multicellular, many are single-celled, like diatoms and phytoplankton.
Let me know if you'd like to learn more about any of these!
