There is no human intereference with the selection of lifescience student. It's just the students with highest averages will be accepted. So your extracurriculars will be of no advantage in terms of admissions, but keep it up anyways
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In the same way, students who took calc in highschool will not be of better standing.
But I suggest you take calculus anways, because if you don't you will have to take the equivilent in university (and pay for the course too
)
Just study hard, aim for 88 - 90% average. Oh and you can retake biology if you want for an ungraded mark
Good luck
I am in life sciences