In general, prokaryotic cells are those that do not have a membrane-bound nucleus. In fact pro-karyotic is Greek for before nucleus. Besides bacteria, the cyanobacteria (blue-green algae) are a major group of prokaryotes.ll living things are composed of cells which are classified as either prokaryotic or eukaryotic cells. The different cell types have many things in common. Enger & Ross's perspective of the common characteristics lists: 1  Cell membranes. 2  Cytoplasm. 3  Genetic material.