THE INFLUENCE OF PROBLEM BASED LEARNING MODEL WITH KEY RELATION CHART MEDIA TOWARD CRITICAL THINKING AND STUDENT’S GROUP COOPERATION IN CLASS VIII SMP NEGERI 14 SURAKARTA ACADEMIC YEAR 2012/2013 - Suciati Sudarisman, Ari Tyas Susanti,Baskoro Adi P, (P Biologi FKIP UNS Surakarta, 2015)