“Sharing ASSETs: Expanding Science Opportunities in K-12 Classrooms” will build upon an established partnership with the NIH (ORIP)-sponsored Tetrahymena Stock Center, an extensive teacher network, and existing infrastructure to expand the scope of the original ASSET program by developing new, innovative, fully evaluated biology curricula for elementary and middle school students. The new lab modules will feature safe, easily grown single-cell protozoa (Tetrahymena) that are ideal for demonstrating many of the basic principles of biology without engendering any of the conflicting reactions often invoked by the use of multicellular organisms in the classroom. To insure that modules meet the needs of teachers and students in schools with varying resources, the modules will be developed, tested, and evaluated in conjunction with teachers drawn from diverse school districts, ranging from small rural schools in economically depressed areas to large city schools serving under-resourced communities. When necessary, module use will be supported by a small equipment lending library that was established as part of the original ASSET program and that will be expanded as part of the new program. This project will also introduce a new approach to independent inquiry for high school students. Using the original ASSET high school modules as a starting point, we will draw upon the expertise of the program staff in the use of Tetrahymena in research, and solicit input from the Tetrahymena research community, to develop an open ended module that provides guidance for teachers in the implementation of independent inquiry as part of their curricula. To insure equitable use by teachers and students in underserved communities with limited facilities, modules will be designed to be as self-contained as possible, and when necessary, will be supported by the equipment lending library. Use of ASSET modules in underserved communities will help stimulate interest in science and science related careers, especially among students traditionally under-represented in STEM activities. In addition to the lab modules, innovative materials addressing the intersection of biology and society will also be developed for use by middle and elementary students. These interactive modules will support the establishment of a scientifically literate, engaged citizenry. In addition, a series of teacher workshops will be carried out to support use of the new ASSET materials, targeting both elementary teachers, who are often not science specialists, and pre-service teachers. The proposed pre-service teacher outreach will support national goals of preparing 100,000 new K-12 STEM teachers by 2020.