I sucked in bio at undergrad. But I ruled in math and physics and the "hard" sciences. (I majored in math and physics before med school.) What I found out when I got to med school is not that I was stupid or that bio was hard, I just found out how to study. You can't study the same way for bio as for math and physics. In math and physics, you study a proof or a theorem, understand it, and then apply it to solve problems. In bio, and medicine you just have to memorize everything. And I mean everything, even itty bitty details that seem to be "obvious." Also, associations are key. For ex, if you read about disease X, and its pathogenesis, it may make sense to you (after all bio/medicine is not hard to understand at all, whereas in math and physics it may take you forever to understand a proof--if you ever end up understanding it) but the key is to also remember that pathogenesis X is associated with disease X and not disease Y. Professors love these association type questions, esp in med school, and I've discovered how they like to test. Or if you encounter an "obvious" fact and they'll ask something like, "Which of the following is true?" and if you did not actively memorize it, you'll be like "Hmm... did I remember reading about that?" Anyway, if you are good at physics and math there is no reason that you would not be able to succeed in bio/medicine. I am just about to finish my second year at med school, and I have to say that med school is a lot easier than the math and physics I was used to, even at an undergraduate level. It's doable. Good luck!