Educational changes in Ontario, initiated by the Hall-Dennis Report, resulted in a public perception of declining educational standards in the 1970's. Ministry of Education Guidelines, which were implemented in an attempt to remedy this, created a major disruption in our grade nine and ten science programmes. The grade ten Life Science course had become fragmented and the classes polarized between bright and slow students. Traditional teaching methods were no longer functioning well and, as a result, students were poorly motivated. In this project, the Life Science curriculum is restructured to improve continuity of subject matter and student motivation. The major innovation is an individualized unit on invertebrate diversity. This modular unit is designed for self-paced mastery learning. The six modules of this unit are based on the Personalized System of Instruction (P.S.I.). Optional activities are incorporated into each module to challenge and motivate industrious students. The means of evaluation of the new curriculum unit are outlined and various criteria for the success of the project are specified. / None / Master's of Science in Teaching (MST)