Are eukaryotic cells multicellular or unicellular?

Eukaryotic cells can be either unicellular or multicellular. Unicellular eukaryotes, such as yeast and protozoa, consist of a single cell, while multicellular eukaryotes, like plants, animals, and fungi, are made up of many cells that work together. The defining characteristic of eukaryotic cells is that they have a nucleus and membrane-bound organelles.