This dissertation uses Bolman and Deal's Four Framework approach to reframing an organization to examine science teachers' beliefs on teacher preparation and reform practices for diverse learners. Despite the national emphasis on "science for all students" in the National Science Education Standards (NRC, 2011), some traditionally underserved groups tend to underperform on standardized measures of science learning (Kober, 2001; Darling-Hammond, 2010; Bracey, 2009; Kozol, 2009, 2007; PCAST, 2012); and teachers struggle to meet the needs of these students (Hira, 2010). The literature is replete with calls for a better understanding of teacher quality as an entry point into increased student achievement in science. In the current study, the 2012 National Survey of Science and Mathematics Education (NSSME) was used to gain an understanding of science teacher quality in the United States, and SPSS 22.0 software was used to evaluate descriptive and inferential statistics, including bivariate correlation analysis, simple linear regression, and a multiple regression of the survey responses. The findings indicated that professional development was the most salient predictor of teachers' preparedness to teach diverse learners. Findings further showed that teachers who held favorable perceptions of preparedness to teach diverse learners were more likely to use reform-oriented practices. This study contributes to an emerging area of research on science teacher quality and its influence on instructional reform for diverse learners. The study concludes with a discussion of supports and obstacles that may enable or inhibit the development of these relationships. [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.]