In Germany with little sister, occupied by ordinary division of cells (7)
I believe the answer is:
mitosis
'division of cells' is the definition.
'mitosis' can be an answer for 'division' (type of cell division). I'm not certain of the 'of cells' bit.
'in germany with little sister occupied by ordinary' is the wordplay.
I cannot quite see how this works, but
'sister' could be 'sis' (synonyms) and 'sis' is present in the answer.
'ordinary' could be 'o' (abbreviation e.g. O-Levels) and 'o' is found within the answer.
The remaining letters 'mit' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for mitosis that I've seen is " Type of cell division".)