<p>Biological and biomedical engineer
Biology
Chemistry...</p>
<p>If “to get in” you mean to schedule your classes and get all the courses you need to major in those fields - no problem. Caltech is of a size that everyone gets the courses they need for their majors, and most all courses can be taken when needed. The only exception is when a lab course has limited lab space, and then they try to schedule enough sections that all students can be accommodated. A few humanities classes book up early, but then they get offered the next term if you didn’t get in the prior term. But no one ever delays graduation because they couldn’t get into their required classes.</p>
<p>If “to get in” you mean to be accepted to Caltech - Caltech does NOT admit by major (called option here). You do not even declare an option till near the end of freshman year, and you can change after that as well.</p>