The rapid advancement of digital learning demands innovative approaches to support students’ higher-order thinking skills. This study aimed to develop and evaluate an AI-based adaptive e-module designed to enhance critical thinking in the Animal Development course. Employing a Research and Development (R&D) approach with the ADDIE model, the study involved 25 biology education students. The module integrated multimedia content, adaptive quizzes, and a chatbot powered by natural language processing to provide personalized learning paths. Expert validation confirmed high feasibility (86%, very feasible) in terms of pedagogy, content, and technology. Implementation results revealed a significant improvement in students’ performance, with average scores increasing from 52.0 (pre-test) to 80.6 (post-test). Statistical analysis showed a significant effect (t(24) = 14.21, p< 0.0001), and the N-gain score of 0.60 indicated a moderate to high improvement. Student surveys further reported high satisfaction, with over 90% positive responses regarding usability, interactivity, and relevance. Qualitative feedback emphasized that the chatbot and adaptive quizzes stimulated reflective and critical learning. These findings demonstrate that AI-based adaptive e-modules can effectively address learning gaps and foster critical thinking in complex biological topics. The study contributes a practical model for integrating adaptive learning and AI into higher education.