Interdisciplinary teaching and learning is an approach that synthesizes the curricular objectives and methods of two or more disciplines or subjects focusing on a specific topic or issue. While it is being increasingly implemented in universities, at lower levels of education there are still countries where science subjects are taught and learned fragmentarily. To assess the significance of the interdisciplinary approach in primary school biology teaching, the paper aims at an experimental verification of the effectiveness of this method in relation to the quality and retention of student knowledge, compared to the monodisciplinary approach to teaching and learning biology. The paper also describes a scenario for teaching a topic in which biological and geographical contents correlate. The study applied a pedagogical experiment with parallel groups. In total, 180 students attending two primary schools in the city of Novi Sad participated in the experiment and were divided into an experimental and a control group. The findings suggest that the interdisciplinary approach improved the quality and retention of student knowledge. The experimental group was more successful in completing tasks that required comprehension and practical application of knowledge. The study thus emphasizes the need for a professional curriculum development that would enhance the interdisciplinary correlation of various disciplines.