<![CDATA[Biology learning becomes meaningful when students can explain how organs, enzymes, and nutrients interact as an integrated physiological system. Yet digestive physiology is often reduced to memorized labels, leaving a representational gap in how learners reason about invisible biochemical processes. Addressing this gap, this study examined the uniqueness of Canva-supported Project-Based Learning (PjBL) as a student-generated visual representation strategy for strengthening critical thinking and cognitive learning outcomes in the human digestive system. A quasi-experimental pretest-posttest control group design was implemented with 66 Grade XI students selected through purposive sampling at a public senior high school in Riau Province, Indonesia. Students were assigned to an experimental class taught through Canva-integrated PjBL and a control class taught through conventional instruction. Data were collected using critical thinking essays, cognitive tests, observation sheets, and student response questionnaires, then analyzed through baseline comparison, independent-samples testing, and normalized gain. Initial ability was comparable between groups (p = 0.385), but the experimental class achieved significantly higher posttest scores in cognitive learning outcomes (82.62 vs. 73.13) and critical thinking (82.52 vs. 73.08), with p < 0.001. N-gain results also favored the PjBL class for cognitive achievement (0.65 vs. 0.47) and critical thinking (0.61 vs. 0.41). High implementation fidelity (95.24%) and positive engagement supported these gains, although scheduling remained a self-regulation challenge (76.14%). The study contributes evidence that digital artifact-based PjBL can move biology instruction beyond recall toward mechanistic reasoning, with broader implications for designing student-centered, representation-rich biology education in complex physiology topics.]]>
