A cell with a distinct nucleus is called a eukaryotic cell.

Here's why:

* Eukaryotic cells are characterized by having a true nucleus, which is a membrane-bound organelle that contains the cell's genetic material (DNA).

* Prokaryotic cells, on the other hand, lack a nucleus. Their DNA is located in a region called the nucleoid, which is not enclosed by a membrane.

So, the defining feature of eukaryotic cells is the presence of a well-defined, membrane-bound nucleus. This makes them distinct from prokaryotic cells.