The study using quasi experimental design involving 160 pre-university students, randomly assigned into experimental (n=80) and control groups (n=80), revealed science writing heuristics approach improved pre-university students' understanding of energy transfer in ecosystems and ability to produce quality arguments. After controlling the pretest scores, the one-way ANCOVA analysis indicates a significant difference between the experimental group's posttest scores taught using science writing heuristics approach, and the control group's posttest scores taught using a teacher-centered approach, in favor of the experimental group. The interview findings denote that the students acquired a comprehensive understanding of energy transfer as they provided holistic explanations describing the energy transfer. The science writing heuristics approach also enabled students to produce quality arguments. The study indicates that the science writing heuristics approach is a viable strategy to facilitate teaching and learning abstract concepts such as energy transfer in ecosystems that fundamentally require students to argue to connect and relate compartmentalized ideas to form holistic views.