This is a "weedout" course
Fact: There are no weedout courses in Biology. No one in this department has an agenda in which they deliberately try to fail some percentage of students. All instructors would be very happy to see all their students pass a class as this reflects well on the instructor. Instructors are also very passionate about their fields of study and actually want others to feel some of that passion, so knowing that students understand the material is very rewarding.
That said, it is possible that BIOL198 does eliminate people from the college ranks. That is not because it is designed that way, but because it is a HARD course. It requires the assimilation of lots of knowledge. It requires students to be consistently dedicated to learning. It requires lots of attention, and the ability to say "no" when some other temptation gets in the way of preparing or studying for this course. People in this course get the grades they EARN as measured in performance on the exams. There are no easy fixes to raise a grade at the last minute (i.e. no extra credit). So students must pay attention to their exam grades and get help early in the semester if needed.