Notes, easily picked up, favouring development of mitosis (10)
I believe the answer is:
fortissimo
'notes easily picked up' is the definition.
I can't judge whether this defines the answer.
'favouring development of mitosis' is the wordplay.
'favouring' becomes 'for' (to be 'for' something is to be in favour of it).
'development of' is an anagram indicator (letters developed in another way).
'mitosis' is an anagram of 'tissimo'.
'for'+'tissimo'='FORTISSIMO'
Can you help me to learn more?
(Other definitions for fortissimo that I've seen before include "with a lot of volume" , "Very loud" , "with greatest force" , "Musical direction" , "Pound notes" .)