bacteria vs spore

bacteria

noun
  • A type, species, or strain of bacterium. 

  • Lowlife, slob (could be treated as plural or singular). 

spore

noun
  • A thick resistant particle produced by a bacterium or protist to survive in harsh or unfavorable conditions. 

  • A reproductive particle, usually a single cell, released by a fungus, alga, or plant that may germinate into another. 

verb
  • To produce spores. 

How often have the words bacteria and spore occurred in a corpus of books? (source: Google Ngram Viewer )