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Unit 21: Bacteria and archaea

About this unit

They're everywhere. They number in the millions of trillions of trillions. They live on every surface, in every environment, and even in your gut. That's right...I'm talking about prokaryotes! Learn more about bacteria and archaea.

Check your understanding of prokaryotes (bacteria and archaea)!


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Prokaryotes may not have complex, multicellular bodies, but they are still remarkably diverse! Learn about the metabolism, ecology, and major groups of bacteria and archaea.