<![CDATA[This study describes the implementation of Problem Based Learning (PBL) in teaching the human respiratory system in senior high school biology. A qualitative descriptive approach supported by simple quantitative data was used. Data were collected through PBL implementation observation, student activity observation, response questionnaires, interviews, conceptual understanding tests, documentation, and field notes. The participants were grade XI B students of SMA St. Arnoldus Janssen. The results show that the PBL syntax was implemented very well, especially in problem orientation, group organization, guided investigation, presentation, evaluation, and reflection. Contextual problems such as respiratory infection, air pollution, smoking, asthma, and shortness of breath encouraged students to connect respiratory organs, breathing mechanisms, disorders, and health maintenance with everyday life. Student activities appeared in discussion, information searching, solution formulation, presentation, and conceptual clarification. The main constraints were limited time, uneven participation, and difficulty understanding detailed breathing mechanisms. PBL can strengthen engagement and conceptual understanding when supported by structured worksheets, visual media, and equitable group roles.]]>
Copyrights © 2026
