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Plants & CreaturesGreekEnglish

Diatom

/ˈdaɪətɒm/noun

A single-celled alga enclosed in a two-part shell of silica.

The Greek roots

διά
diá
through, apart
+
τέμνειν
témnein
to cut

Literally: cut in two

The story of the word

The name describes the shell: two glass halves that fit together like a petri dish and its lid. When the cell divides, each daughter keeps one half and builds a smaller new one inside it, so a line of diatoms shrinks slightly with every generation until sexual reproduction resets the size. The same verb cuts through atom and anatomy.

How it travelled
Ancient Greek → scientific coinage → English
First recorded
1840s

Same family

atomanatomyepitomedichotomy

In a sentence

Diatomaceous earth is a quarry of dead diatoms, each one a glass box.

Built on the same root

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