genetics on the macro level (Simmons and Lunetta 1993), or consist of a database of questions, both on the micro- and macro-levels, that were translated into computer pro- grams (Lu et al. 1997). In this study we chose to investigate, empirically, whether a supplement of computer animation in molecular genetics’ instruction in high school can enhance students’ understanding of genetic concepts and processes. We also elaborate on different activities and their potential contribution to students’ conceptual understanding.