Construction and practical implications of an interdisciplinary teaching path for DNA diffraction patterns—from the perspective of scientific history and principle visualization

DNA diffraction patterns are critical evidence for the DNA double helix and an interdisciplinary bridge linking biology, chemistry and physics. To address gaps in high school biology teaching including ambiguous pattern-structure reasoning and fragmented cross-disciplinary learning, this research builds a three-stage teaching path guided by situated cognition, constructivism and NGSS. It traces the historical discovery of DNA diffraction from Astbury to Franklin, clarifies mappings between X-ray diffraction rules, diffraction images and DNA structures, and develops history-based inquiry, visual experiment and interdisciplinary teaching strategies. A pre-post test with 95 students from three Xinjiang high schools was implemented. After intervention, students’ accuracy in deducing DNA structures from diffraction patterns rose from 42.10% to 57.55%, and their interdisciplinary integration scores improved from 47.52% to 62.11%. The validated teaching path strengthens students’ evidence-based reasoning and scientific inquiry literacy, offering a replicable interdisciplinary teaching model for global biology classrooms.