Promoting Active Learning Strategies (PALS) in Biology is a two year project funded by the National Science Foundation (DRL#1417735) to improve learning and ultimately end-of-course scores in Biology. The approach involves using active learning strategies to engage students in learning Biology. Two strategies, one developed in chemistry and one in physics, will be examined. Process Oriented Guided Inquiry Learning (POGIL) was invented by chemist at Franklin & Marshall College in Pennsylvania. Peer Instruction (PI) was invented by physicists at Harvard University. A group of teachers will learn and use each of the strategies to examine their impact on the learning of concepts under Cells and Heredity in Biology I. We prefer to enrole teacher teams (of two) or more from a school, all using the same strategy. Schools will be assigned randomly to a strategy.