Background: While much literature has argued for the value of carefully designed instructional units building on student resources, less work details how students' own invocation of experiences and ideas from their everyday lives plays out in naturalistic classroom dialogues. Employing a sociocultural and interactional approach, this article illuminates how student resources become mediational means in ways that support learning. Methods: The empirical basis constitutes whole-class conversations involving lower secondary school students and their teacher during a science project about genetics. The applied analytical procedure involves microanalyses of sequences of student-teacher interaction in settings where students invoke resources from their everyday lives. Findings: The findings demonstrate that student resources became mediational means that (a) enabled students to express and test out their conceptual understanding and scientific reasoning, (b) promoted student participation and curiosity, and (c) positioned students as authoritative and accountable participants in whole-class conversations. Furthermore, how student resources became mediational means was also dependent on the distribution of authoritative roles between students and the teacher. Contributions: This article provides evidence for the value of invoking student resources in educational dialogues and displays both how they can support learning and the challenges teachers may face in doing so.