Here's a breakdown:
* Prokaryotic cells lack a membrane-bound nucleus. Their genetic material (DNA) is located in a region called the nucleoid, which is not enclosed by a membrane.
* Eukaryotic cells have a well-defined nucleus that contains their DNA, separated from the rest of the cell by a nuclear membrane.
This fundamental difference in cellular organization leads to many other distinctions between prokaryotes and eukaryotes, including:
* Organelles: Eukaryotes have a wide variety of membrane-bound organelles, such as mitochondria, Golgi apparatus, endoplasmic reticulum, etc., that perform specific functions. Prokaryotes lack these specialized organelles.
* Size: Eukaryotic cells are typically larger than prokaryotic cells.
* Complexity: Eukaryotic cells are more complex in structure and function than prokaryotic cells.
In summary, the presence of a true nucleus is the defining characteristic that separates prokaryotic and eukaryotic cells.
