This study investigates and compares knowledge types in national curricula embedded in the curriculum tradition (England) and the didactic tradition (Finland and Sweden). In the study, we develop and operationalize a theoretical framework based on educational purposes (academic, citizenship and humanistic purposes) and knowledge categories (substantive, disciplinary, sociocultural applications, pedagogical considerations and student-psychological considerations). The framework is thus embedded in a didactical perspective on powerful knowledge and is used as an analytical lens in a quantitative content analysis, and a consecutive qualitative analysis providing 'thick' descriptions of the biology curricula for each country providing a contextual interpretation of the results. From the analysis, we can conclude that the curricula are different and identify different aspects of knowledge. The English curriculum mainly identifies the products and processes of biology to teach. The Finnish curriculum has a holistic approach connecting the products and processes of biology, with the teaching and learning process and how students should apply the knowledge in society. The Swedish curriculum could be described as a hybrid of the English and Finnish ones focusing on the products and processes of biology and how this knowledge can be applied in society. Implications for teaching and learning are discussed.