Assumes, takes up (6)
I believe the answer is:
adopts
I believe this clue is a double definition.
'assumes' is the first definition.
('adopt' can be a synonym of 'assume')
'takes up' is the second definition.
('adopt' can be a synonym of 'take up')
(Other definitions for adopts that I've seen before include "Legally takes on (child)" , "Approves or accepts, a motion or accounts" , "Takes as heir or representative" , "Takes into one's family legally" , "Takes or uses as one's own" .)