No. Both grades will remain on your transcript and both will be averaged into your GPA. If you need to repeat a course to bring up your grade to meet prerequisite or major requirements (you can see more about grade requirements here), that is fine. Students in the College of Natural Sciences are not permitted to repeat a course for which they have already earned a C or better (with the exception of CS entry-level courses). In addition, no student may enroll in the same Natural Sciences course more than twice without permission from their advisor, therefore students taking a Natural Sciences course for a second time need to be aware it may be their last chance to pass that course.