Dropping out the first year of biomedicine and going into medicine

If I take a gap year and enroll in biomedical science for example to make the year more productive, would it be possible for me to drop out of that course if I get accepted into medical school during the year? Basically, I’d like to study something while applying to med schools, but I’m not sure if it’s okay to leave the course partway through if I get in.
And just a FYI I’m taking a gap year because my UCAT didn’t go so well and I don’t want to apply to med school as a post grad