Here's why:

* Prokaryotic cells are simple, single-celled organisms that lack a membrane-bound nucleus and other membrane-bound organelles. Their genetic material (DNA) is located in a region called the nucleoid, which is not enclosed by a membrane.

* Eukaryotic cells, on the other hand, are more complex cells that contain a true nucleus where their DNA is enclosed within a membrane.

Examples of prokaryotic organisms:

* Bacteria

* Archaea

Key differences between prokaryotic and eukaryotic cells:

| Feature | Prokaryotic Cells | Eukaryotic Cells |

|---|---|---|

| Nucleus | Absent | Present |

| Organelles | Few or none | Many |

| DNA structure | Circular | Linear |

| Size | Smaller (1-10 micrometers) | Larger (10-100 micrometers) |

| Examples | Bacteria, Archaea | Animals, plants, fungi, protists |

Let me know if you'd like more information on prokaryotes or eukaryotes!