Writing-to-learn (WTL) is an effective instructional and learning strategy that centers on the process of organizing and articulating ideas, as opposed to writing-to-communicate, which centers on the finished written product. We describe a WTL model that we have developed and tested with various student groups over several years. With effective instructor guidance (through prompts and in-class discussion), students demonstrated greater scientific literacy after participating in writing activities about engaging socio-scientific issues. We believe that WTL activities are underused in secondary and post-secondary biology courses. (Contains 1 table and 1 figure.)