Simplest form of life in zoo or apt compound (8)

I believe the answer is:

protozoa

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'simplest form of life' is the definition.
I can't judge whether this defines the answer.

'zoo or apt compound' is the wordplay.
'compound' is an anagram indicator.
'zoo'+'or'+'apt'='zooorapt'
'zooorapt' with letters rearranged gives 'PROTOZOA'.

'in' acts as a link.

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(Other definitions for protozoa that I've seen before include "E.g. flagellates" , "Unicellular creatures" , "Class of tiny organisms" , "Very large plant" , "Single-celled organisms" .)

I've seen this clue in The Telegraph.

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