1. Ribosomes: These are the protein synthesis factories of the cell. Both prokaryotes and eukaryotes need ribosomes to translate genetic information from mRNA into proteins. While the ribosomes in each cell type are different in size and composition, they both perform the same fundamental function.

2. Plasma membrane: This is the outer boundary of the cell, controlling what enters and exits the cell. Both prokaryotes and eukaryotes have a plasma membrane, though the composition and structure may differ slightly. This membrane plays a crucial role in maintaining the cell's internal environment.