It would have helped if you had mentioned your CAT percentile but if you have got a profile-based call the ball is technically in your court, your good academic profile and extracurricular background would certainly give you enough topics to discuss in your GDPI process. And keep in mind that today most of the B-Schools are diversifying their students profiles which again gives you an edge because of your biology background.
SPJIMR usually has a cutoff of around 85 percentile in CAT for profile-based shortlisting and you gotta outperform others in the further rounds if your percentile is anywhere between 85-90.