What feature is unique to prokaryotic cells compared to eukaryotic cells?

The unique feature of prokaryotic cells compared to eukaryotic cells is the presence of a nucleoid region for genetic material. In prokaryotes, DNA is located in the nucleoid, which is not surrounded by a membrane. This contrasts with eukaryotic cells, where the genetic material is contained within a membrane-bound nucleus. The nucleoid allows for a simpler organization of genetic material, reflective of the generally less complex structure of prokaryotic cells.

In addition, prokaryotes typically lack other membrane-bound organelles, such as mitochondria, and do not have a complex endomembrane system, which features prominently in eukaryotic cells.