IB student wanting to go to Canada

Hi!

Im an IB student and have applied for Computer Science in Canada, my predicted grade is 36, however my mid year grade is around 31, this is mainly because the teachers keep marking me down i have no idea why. Anyway, I wanted to see what my chances are to get into universities like University Of Toronto, UBC, McGill and Waterloo. Since some of them (UofT and McGill) have asked for my mid year grades will it affect my overall chances of getting in?