["Journal of Research in Science Teaching, Volume 63, Issue 4-5, Page 332-351, May 2026. ", "\nABSTRACT\nQueer undergraduates describe a climate in STEM fields and classrooms that is both hostile to and silent on queer identities, leading to experiences of social exclusion, devaluation as a scientist, and discrimination. In the few studies that have specifically focused on trans and non‐binary undergraduates (i.e., students with queer genders), these students report more hostile conditions than their cisgender peers. In biology and biology‐related majors, where core courses include topics related to sex, gender, reproduction, sexual behavior, and sexual and romantic orientation, the content itself may influence a student's experience. Yet, biology is the study of the diversity of life, including diversity across sex, gender, reproduction, sexual behavior, and orientation, which also makes course content a prime site for narratives that support students with queer identities. We employed Master Narrative theory to understand the narratives about sex, gender, reproduction, sexual behavior, and orientation present in undergraduate biology courses through interviews with biology majors with queer genders. We identified three narratives that both supported the belonging of students with queer genders and had the ability to challenge harmful societal narratives. These three narratives could manifest in the classroom in multiple ways, ranging from short disclaimers to elaborate case studies involving human examples. The ways the narratives manifested impacted their efficacy for at least some participants. These narratives and how they manifest provide potential starting points for designing interventions to support students with queer genders in biology classrooms and more accurately teach the biology of sex, gender, reproduction, sexual behavior, and orientation.\n"]