Final answer:
Ribosomes are the only universal organelles found in both prokaryotes and eukaryotes, as they are crucial for protein synthesis and unlike other organelles, they are not membrane-bound.
Step-by-step explanation:
Ribosomes are organelles that are found in both prokaryotic and eukaryotic cells. They are the sites of protein synthesis, where amino acids are assembled into polypeptide chains. Ribosomes are not surrounded by a membrane like other organelles found in eukaryotic cells.
The universal organelles found in both prokaryotic and eukaryotic cells are ribosomes. Ribosomes are the sites of protein synthesis and are not surrounded by a membrane, which distinguishes them from other organelles such as the nucleus, mitochondria, and Golgi apparatus that are found only in eukaryotic cells. Mitochondria are referred to as the power plants of the cell because they are responsible for ATP production through cellular respiration, which is crucial for energy supply within the cell. Prokaryotes lack these membrane-bound organelles but still require ribosomes for protein synthesis, underscoring the essential nature of this organelle for all life forms.