2025-08-122025-08-122022https://repositorio.ifal.edu.br/handle/123456789/1128The search for meaningful learning continues to be a challenge for many teachers, who need to plan their classes with the objective of achieving teaching that meets the needs of students. This work aimed to propose a didactic sequence for the teaching of "cytology" in the 1st year of high school, based on the Theory of Didactic Situations (TSD), having as a starting point the use of a homemade microscope. The methodology involved a qualitative and bibliographical research, seeking to suggest a teaching model based on TSD, which consists of the application of four phases: action, formulation, validation and institutionalization. The proposal is promising and can be applied in different curricular contents.ptSequência DidáticaMicroscópico CaseiroTeoria das Situações Didáticas.Trabalho de Conclusão de CursoCIENCIAS BIOLOGICAS