Listed are guidelines for the steps in the development of a flexible long-range senior science curriculum. The program is separated into biology, chemistry, and physics, and a course outline is given for each. These outlines are not committed to any one approach, but draw on the many curriculum improvement projects and other sources. The emphasis is on laboratory experiences which emphasize principles, concepts, the nature of scientific investigation, and the undertainities inherent in scientific work. The outline is suggestive rather than prescriptive and is designed to allow the teacher flexibility in designing his own program. A science curriculum flow chart shows the proposed sequence of courses for grades 7-12, with suggestions for possible points of termination for various students. Basic, general, and accelerated programs are identified. (GR)