The pupil in the back room is a dope (7)
I believe the answer is:
monitor
'the pupil' is the definition.
(thesaurus)
'in the back room is a dope' is the wordplay.
'in' indicates putting letters inside.
'the back' is a reversal indicator.
'is a dope' becomes 'nit' (I can't justify this - if you can you should give a lot more credence to this answer).
'room' in reverse letter order is 'moor'.
'moor' enclosing 'nit' is 'MONITOR'.
Can you help me to learn more?
(Other definitions for monitor that I've seen before include "Vet" , "Keep track of" , "Sort of lizard" , "Security camera" , "Police" .)