If there is a year-long sequence, like single variable calculus, a quarter system (at least the way it is done at UCLA) divides the 30 weeks of instruction into three 10-week quarters, while a semester system divides the 30 weeks of instruction into two 15-week semesters.
You take more courses under the quarter system, but each one will be “smaller”.
Biology does not have particularly good job prospects for bachelor’s degree graduates. If you need to take substantial debt to attend either school, you may want to reconsider and choose a less expensive school. If you are pre-med, you may want to note that medical school will probably cost $400k or so, so you probably do not want to add undergraduate debt to that.