The Foxes took the lead in Friday night's clash at the Walkers Stadium after 15 minutes when Steve Howard's header from a Max Gradel corner was blocked with the ball falling to Morrison, who fired in from five yards.
Scunthorpe were level after 57 minutes when Martyn Woolford was allowed to get in a low cross from the right which Paul Hayes slotted in from seven yards.
The visitors went in from eight minutes later when Foxes substitute Bruno Berner was ruled to have hauled down Hayes inside the box.
Grant McCann confidently stroked in the penalty for his 12th of the season with Foxes keeper David Stockdale diving the wrong way.
City levelled 14 minutes from time when Jack Hobbs, who earlier agreed a permanent move to the Foxes from Liverpool, nodded a Matt Oakley free-kick across the face of goal for Morrison to head in from five yards.