Teacher education has made strides towards preparing preservice teachers with ambitious visions and teaching practices through the use of core practices, specifically the Ambitious Science Teaching (AST) framework (e.g. Kang & Windschitl, 2018). However, there is an argument in the field about whether the AST framework can support justice-centered PST development (Kang & Zinger, 2019). There is limited research on preservice teacher development within justice-centered AST programs, which moves beyond the goal of merely providing access to authentic science learning to all children by (1) challenging the traditional Eurocentric view of science and (2) using science class to improve societal problems. The purpose of this study was to explore experiences that teachers consider to be transformational, in and beyond their teacher education program, as they develop (or do not) as justice-centered ambitious science practitioners. This qualitative case study explored such development in two cohorts of recent graduates from an intentionally designed Masters program that attempted to integrate social justice within the AST framework. Retrospective preservice artifacts and interview transcripts were examined for evidence of transformational learning, (i.e. learning that changes a person's frame of reference or deep beliefs) and critical consciousness (i.e. recognizing inequity and taking action against it). Findings include that novices' teaching practices fell into three categories: justice-centered and ambitious, ambitious only or neither justice-centered nor ambitious. Additionally, findings suggest that once novices recognized systemic inequities, some responded by teaching in ways that challenged traditional narratives in science and school while using AST practices and tools. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]