Discussion sections are scheduled course meetings led by a teaching assistant (TA). Goals of these meetings may include: providing additional content practice, access to instructional support, and promoting a student's sense of belonging. As such, sections ideally include smaller groups of students and involve active learning. However, little is known about broad patterns in discussion section instruction and student experiences. To characterize student experiences in discussion sections, we surveyed ∼5000 students enrolled in 19 different biology courses covering 193 discussion sections at one institution in spring and fall 2023. Discussion sections varied in size (32 - 400 + students) and modality, with students participating either in-person or remotely. Students in remote discussion sections reported receiving significantly higher amounts of lecture from TAs compared with students in in-person sections, and these shifts in activity significantly modified their sense of belonging. Inductive thematic analysis of qualitative responses identified several themes regarding aspects of discussion sections that students felt were helpful (e.g., increased access to support) or unhelpful (e.g., environments not conducive to learning). Our findings offer insights into the different ways discussion sections are used in large biology programs and provide data to inform future discussion section design.