Here's why:

* No Nucleus: Prokaryotic cells lack a membrane-bound nucleus, unlike eukaryotic cells.

* Circular DNA: Prokaryotic DNA is typically a single, circular molecule.

* Nucleoid Region: The nucleoid is a non-membrane-bound region within the cytoplasm where the DNA is concentrated. It's not a separate compartment like a nucleus, but rather a dense area where the DNA is organized and compacted.

So, while not enclosed in a nucleus, the DNA in prokaryotes is still localized and organized within the cell.