Choosing university courses is merely a six-word affair—
quick hands get, slow hands miss.
Typically, the courses with room for selection are the non-core classes like sports and electives; not getting these won't cause much harm.
But for Yingpei, their core curriculum only has five types of general courses within the department, and nearly half of their other courses must be chosen by the students themselves, and all are counted as official credits.
For instance, if you took some physics courses, and later switched to the School of Physics, you wouldn't need to take those courses again.
Conversely, if you had studied biology courses beforehand, that would essentially have been in vain.
Of course, that's just considering things from a graduation and credit perspective; if you have a physicist who understands biology well, God knows what they could achieve.