It is important to know how current education affects students’ attitudes towards learning, specifically in a quickly evolving and societally relevant field of biology such as genetics. The aim of this study is to examine how teacher and student-related factors explain secondary school students’ attitudes towards the applications of genetics and learning in genetics. In total 421 students aged between 17 and 20 from ten schools participated in the study. We measured students’ liking of, self-concept in and experienced utility of genetics and students’ attitude towards gene technology and belief in genetic determinism. We carried out item response theory based modelling by including teachers’ teaching emphases, learning materials, student gender and the number of attended biology courses as explanatory variables. The attitude towards gene technology and belief in genetic determinism correlated with all independent factors. Male students’ attitude towards gene technology was more liberal; they had higher self-concept, but experienced less utility in genetics and their belief in genetic determinism was weaker than in women. If the teacher’s emphasis was on Heredity or if the textbook with stronger Mendelian emphasis was used in teaching, students had more negative attitudes towards learning in genetics, but the belief in genetic determinism was stronger. In comparison, teacher’s Developmental emphasis explained students’ lower belief in genetic determinism, whereas Structural emphasis correlated with students’ liking of genetics. The results suggest that teachers’ approaches in genetics teaching as well as learning materials need updates to fulfil the needs for genetics literacy in current science education.