For our Introductory Biology lecture courses, faculty developed activities for use in peer-led team learning based recitations. The materials were designed to help students master concepts instructors identified as challenging for students. Hands-on activities were developed for many of the lessons. Many of the activities were developed with the intention of providing students with opportunities to develop critical thinking skills and practice data analysis and interpretation. Students need opportunities to practice both skills in order to improve in these areas. Questions on course exams were also developed to reflect the use and development of these particular skills. The materials developed for our program are provided in the links below for your use. Feel free to adapt them to best meet your course needs. Teaching tips for peer facilitators and notes for the instructor are included in each activity below. We have not included answer keys as we feel it is important for instructors and peer facilitators to actually do the exercises at least once before attempting them with a class. Our peer facilitators complete the activities in weekly group meetings as small groups, just as they will teach it in the upcoming week. This allows time for the course instructor to check their understanding and clear up any misconceptions they may have before they facilitate the lesson themselves.