IMO, courses generally fall into two categories - the ones where a grade distribution comes from different levels of effort, and the ones where the distribution comes from different levels of ability/understanding.
Courses in psych, for example, tend to be effort-based. There's not a lot of really difficult conceptual stuff in a class on Abnormal Psych, for example, so doing well on a test is going to involve many study hours where you memorize all sorts of DSM criteria, drug names, etc. Nobody does badly on a test because they can't "get it", only because they didn't memorize some piece of information they needed. What separates the A from B from C students is whether they put in the effort to memorize everything, and a student who studied 20 hours is very likely to beat out another who studied for 2 (barring something like photographic memory).
Much of the prereq series topics, esp. Physics/Calc or parts of Chem/Ochem, tends to fall on the other side and be ability-based. People can come into an exam with full knowledge of all equations or mechanisms, yet do badly because they don't have the puzzle-solving ability when presented with novel problems. In a lot of cases, equations will even be provided, and what separates the A from B from C students is how well they "get it" and can problem solve at high speed relative to the others in the class. This is where you can see that frustrating phenomenon where your freak room mate reviewed for an hour while you slaved away all weekend, yet they beat you by a mile on the curve by having insights and creative reasoning that never occurred to you.
Of course there are many cases that fall somewhere in the middle, like Biochem, where you can't do well without both a metric **** ton of memorization and some insights into challenging problems that most people miss.
If you want the highest odds to make a 3.7+ GPA against the kids at Cal, take classes like the first category, and put in the study time.
Cal is def Berkeley not CalTech. They use that nickname to show off that they were the OG UC, founded 50+ years before UCLA