* Cell wall: Protists, plants, and fungi often have cell walls for structural support and protection. Animal cells lack cell walls.

* Mitochondria: These are the "powerhouses" of the cell and are found in all eukaryotic cells, including protists, plants, fungi, and animals.

* Plasma membrane: This is the outer boundary of all cells, both prokaryotic and eukaryotic.

* Ribosomes: These are essential for protein synthesis and are found in all living cells.

In summary: The presence of a cell wall is a defining characteristic that distinguishes many protists, plants, and fungi from animals.