At the beginning of this lesson, we talked about a recent case of a superbug: a strain of Klebsiella that was resistant to all twenty-six of the available antibiotics.

Remember, prokaryotes represent a broad spectrum of organisms. This video teaches us about the (mostly) single-celled organisms that make up two of the three taxonomic domains of life, and one of the four kingdoms: Archaea, Bacteria, and Protists (which we’ll learn about in the next module). They are by far the most abundant organisms on Earth, and are our oldest, oddest relatives.