Kids with one parent and one science graduate on voyage evidently? (7)
I believe the answer is:
sibship
'kids with one parent' is the definition.
(sibship can mean a group of animal siblings)
'one science graduate on voyage evidently?' is the wordplay.
'one' becomes 'I' (Roman numeral).
'science graduate' becomes 'BS' (holder of Bachelor of Science degree).
'on' is an insertion indicator.
'voyage evidently?' becomes 'ship' (I am not sure about this - if you are sure you should believe this answer much more).
'i'+'bs'='ibs'
'ibs' going within 'ship' is 'SIBSHIP'.
'and' acts as a link.
(Other definitions for sibship that I've seen before include "Group with same parents" , "Brothers share this" .)