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 survey study is to examine how school 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 used a modified version of the Fennema–Sherman Attitude Scales to measure students’ liking of, self-concept in and experienced utility of genetics and a modified version of the Biohead-Citizen questionnaire to measure attitudes towards gene technology and beliefs in genetic determinism. As explanatory variables, we used their teachers’ teaching emphases and learning materials based on our earlier study, and as student-related factors, we used gender and the number of biology courses. Item-response theory with exploratory, confirmatory, and explanatory analyses were carried out to model the data. The attitudes towards gene technology and beliefs in genetic determinism were correlated with all used variables. Male students’ attitudes towards gene technology were more liberal; they had higher self-concept, but experienced less utility in genetics and their beliefs on genetic determinism were weaker than in women. Teaching explained students’ attitudes and beliefs: 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.