Experimentation is a complex problem-solving process. In biology lessons, experiments involve creative thinking and open discovery; however, they still require some degree of instructional guidance. The right balance between discovery learning and instructional guidance depends substantially on students' prior knowledge. Students with low prior knowledge in particular might have difficulties with conducting and understanding experiments. Incremental scaffolds might be a valuable tool to meditate between pure discovery and strong guidance while simultaneously taking learners' individual knowledge and skills into account. In the current study, we examined the effects of incremental scaffolds (IncSc), no scaffolds (NoSc), and worked-out examples (WoEx) on students' knowledge acquisition while doing inquiry-based experimentation with a special focus on students with low prior knowledge. In a pre-posttest design, 193 students (M[subscript age]= 13.02 ± 0.81 years) participated in a four-hour teaching unit on animals' overwintering strategies. In the pre- and posttest, we assessed the students' conceptual and procedural knowledge. Our results partially confirmed our hypotheses: Regarding the conceptual and procedural knowledge of all students, incremental scaffolds showed no additional benefit regarding students' knowledge in the posttest when compared to working with no scaffolds or worked out examples. For the students with low prior knowledge, working with incremental scaffolds led to higher conceptual and procedural knowledge after the teaching unit than working with worked-out examples.