What Is the Difference Between a Protozoa and a Bacteria?

By Staff WriterLast Updated Apr 5, 2020 9:20:37 AM ET
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Bacteria and protozoa are very distantly related, with bacteria classified as prokaryotes and protists as eukaryotes. This means that protozoa are more closely related to humans than either is to bacteria. The two organisms are structurally distinct. Bacterial cells lack a nucleus, and protozoa contain organelles, such as mitochondria.