However, it's important to note that the classification of organisms into kingdoms is constantly evolving. Modern classification systems often place prokaryotes into two separate domains:

* Bacteria: These are true bacteria, a diverse group of single-celled organisms.

* Archaea: These are single-celled organisms that are often found in extreme environments and have unique biochemical properties.

While the Monera kingdom is a traditional classification, the domain system is more widely accepted today.