prokaryotic cells

• the cell wall is the rigid outer covering which is made of peptidoglycan

  
• The capsule is a protective slimy layer which helps the cell to retain moisture and adhere to surfaces.

  
• The plasmid is a circular piece of DNA

  
• the flagellum is a tail like structure which rotates to move the cell

  
• Pili are hair like structures which attach to other bacterial cells

  
• ribosomes are the site of protein production