Here's why:

* Simple and small: Prokaryotes are the simplest and smallest type of cells. They lack the complex internal structure found in eukaryotic cells.

* No nucleus: The defining characteristic of prokaryotes is the absence of a membrane-bound nucleus. Their genetic material (DNA) is located in a region called the nucleoid, but it's not enclosed within a separate membrane.

Examples of prokaryotes include:

* Bacteria

* Archaea

Let me know if you have any more questions!