Science, Technology, Engineering, and Mathematics fields have incredible impacts on society and the planet. One example of such a field is synthetic biology—a modern biotechnology that involves the, often genetic, manipulation of cells or cellular outputs for practical purposes. This field influences agriculture, medicine, and manufacturing—to name a few. Concomitant with these advancements is the rise of professional communities and university level academic areas of study around synthetic biology. These activities—until recently—have been limited to commercial groups and experts due to the material and intellectual resources needed for field engagement. The emergence of lower cost portable lab tools, local community lab spaces, and interactive public exhibits has made synthetic biology accessible to field novices of all ages. Despite, there is little research that examines the affordances synthetic biology may provide K-12 learners. In fact, much of existing research related to K-12 learners often includes applications that have advanced considerably or that do not include synthetic biology. Moreover, much of existing research reports on high school students, while far less examines middle school students who have previously been shown to have well-formed perspectives about biotechnologies. The research presented in this thesis attends to this gap in the literature by addressing three overarching research questions, including: (1) what do middle school students know and think about synthetic biology and its various applications, (2) how do middle school students carry out synthetic biology as an active learning activity, and (3) how do synthetic biology-related contexts clues support student justifications about their perspectives? Mixed-methods are used to examine surveys, semi-structured interviews, video observation data, and student productions. Results suggest that while middle school students know very little about synthetic biology and its various applications, their well-formed opinions about the field include considerations of application utility, risks, benefits and safety. Findings also suggest that synthetic biology provides opportunities for learners to engage in personally relevant production and—when situated in detailed contexts—supports advanced justification practices. Priorities for future research and innovations in synthetic biology and science education are discussed.