List five examples of a prokaryotic cell?

Prokaryotic cells are ones that don't really have a nucleus, Golgi apparata, mitochondria, flagella, etc. Things like bacteria. So...

Helicobacter pylori
Listeria monocytogenes
Chlamydia trachomatis
Haemophilus influenzae
Legionella pneumophila

Note they are only the bacteria which attack humans (because they're the ones I tend to know). There are millions of others to choose from. Or you could choose archaea, which are also prokaryotes.