prokaryotes
The rod-shaped organisms in Figure below are bacteria called Salmonella . Bacteria bacterium, singular are prokaryotes in the Bacteria Domain. The word Salmonella may sound familiar. That's because Salmonella is a common cause of food poisoning. Many other types of bacteria also cause human diseases. But not all bacteria are harmful to people. In fact, we could not survive without many of the trillions of bacteria that live in or on the human body. You'll learn why when you read this lesson.