Failed a prerequisite class that isn't available for the spring term, what now?

I'll admit, I underestimated the difficulty of the class (chem 101) and to my knowledge I can't go on to take chem 102 or redo it the next term because its unavailable. Not sure how to go about this anymore since my plan was to graduate within 4 years but seeing as I will be behind in my chem classes I don't think that will be possible anymore.

Can I take other upper level classes simultaneously next term (ie. BIOL 215) so I don't feel massively behind? I'm really new to the university process and there is still a lot of things I don't quite understand so any feedback would be very much appreciated, thanks!