教学前后学生对有关生物学概念都有自已特定的理解，这虽与公认的科学理论不一致，但学生往往不仅不会轻易放弃这些概念而接受教师和书本上的观点，而且还会倾向于将课堂中呈现的材料和现象纳入自己原有的认知结构，曲解有关内容。造成这种“先入为主”的因素是多种多样的，现 Before and after teaching, students have their own specific understanding of biological concepts. Although this is inconsistent with the generally accepted scientific theory, students often do not simply give up these concepts and accept the opinions of teachers and books, but they also tend to use classroom teaching. The materials and phenomena presented in it incorporate their own cognitive structure and misrepresent the relevant content. The factors that cause such “preconceptions” are various and they are now