Which cell observed that lack membrane-bound internal organelles?

Prokaryotic cells are observed to lack membrane-bound internal organelles. Unlike eukaryotic cells, which contain structures such as the nucleus, mitochondria, and endoplasmic reticulum enclosed by membranes, prokaryotic cells, such as bacteria and archaea, have a simpler structure. Their cellular processes occur in the cytoplasm or at the cell membrane, without compartmentalization by organelles.