Question

Question #0645e

Answer 1

Bacteria is plural,
Bacterium is singular.

Explanation:

Bacteria and Bacterium both refer to the same thing: Microscopic prokaryotic cells with no nucleus. However, if you wanted to talk about these cells in the plural, you would say "the bacteria" or "these bacteria." If you wanted to talk about these cells in the singular, you would say "a bacterium" or "this bacterium." You would never say "a bacteria" or "bacterias."

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