How hard does the prereqs actually get?

I'm a freshman in MCB (my school divides biology into MCB and IB), an introductory chem class, statistics, and an English composition class. How hard do prereq classes actually get? I'm hoping to achieve anywhere around 3.7 cumulative with my prereq courses.
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Tags: Pre-Dental Source Type: forums