General Characteristics
Unicellular, absorptive-heterotrophic, photoautotrophic, or chemoautotrophic prokaryotes.
Only one set of genes, usually in a single-stranded loop.
Lack sexual reproduction.
Several chemical types of cell walls.
Lack organelles such as centrioles, eukaryotic flagella, cilia, mitochondria, and chloroplasts.
Some bacteria have a unique type of rotating flagellum.
Photoautotrophic species have chlorophyll, but not chloroplasts (which are organelles that are separated form the surrounding cytoplasm by their own membranes).