ABSTRACTThe development of critical thinking skills is one of the core values of higher education. As an important aspect of visual literacy in the core competencies of undergraduate biology teaching, diagram learning activities have been shown to facilitate students’ gains in understanding biology concepts and improving critical thinking skills. To address a need to scaffold students’ learning processes of the higher-order cognitive skills in Bloom’s Taxonomy via diagram, we have developed an instructional tool using diagrams for online and in-person classes. This teaching and learning tool utilizes a digital canvas created in Microsoft Whiteboard. A diagram of a certain complexity is designed and created by the instructor to model the critical thinking linked to the taught content. Students can work simultaneously to fill in the blanks of the diagram using provided terms and phrases that are derived from lecture slides and aligned with course learning objectives. A moderator, either a peer leader or the instructor, can use this online whiteboard to observe and advise students for their study activities and engage students in discussions in real-time. This customized teaching tool may be particularly useful for introductory biology courses to train first-year students and sophomores to learn biological concepts and mechanisms. More importantly, it helps students comprehend and learn the critical thinking skills embedded in the provided diagrams to prepare them to conduct more complex diagram activities and generate their own diagrams.