Ha the teacher called a kid in my Maths class a "knobhead" in front of the whole class as he caught the kid cheating off the markscheme. Safe to say he got a lot of stick that day Oh and he got sent to the head of department's office and his parents got called in lol
What grade and tier would they give you for that subject once they found out you cheated in the mock?
Every school will have its own policy on this and will decide what to do about anyone discovered cheating after an assessment of the facts. Action could range from nothing more than a serious telling off (the most likely result) through to suspension (or worse) and/or withdrawal of exam entries for the subject. They will probably look for evidence of malpractice in your other exams. They are likely to give you no mock grade for that subject and enter you for the tier that their previous predictions deemed appropriate.