In collaboration with researchers from the University of Kentucky, Heidi Anderson, AP Biology teacher at Paul Laurence Dunbar High School in Lexington, KY, has developed an inquiry-based investigation of heart rate. What makes her approach unique is she studies crayfish. Students connect a Vernier EKG Sensor to leads attached under the dorsal carapace of the crayfish, near the heart. Some sample data and images are shown. Heidi’s students develop experiments, using the crayfish, to investigate variations in heart rate due to environmental changes such as depth of water, temperature, exposure to air, exercise, and social response.