Here's why:

* Eukaryotic cells have a true nucleus that contains their DNA, as well as other membrane-bound organelles like mitochondria and Golgi apparatus.

* Prokaryotic cells lack a nucleus and other internal membrane-bound organelles. Their DNA is located in a region called the nucleoid.

Bakers yeast (Saccharomyces cerevisiae) is a single-celled fungus, and fungi are classified as eukaryotes.