Abstract
In recent years, research related to critical thinking has increased significantly. The new educational paradigm emphasizes the development of 21st-century skills, one of which is critical thinking, declaring it a fundamental skill for learning in the 21st century. Critical thinking is a set of skills that need to be integrated into all disciplines so that students can become aware of their own thought processes, make informed decisions about their future development, and take responsibility for the consequences of their actions. The biology curriculum provides students with this opportunity by placing them in situations where they have to solve biological, environmental, and health problems, propose solutions, analyze, and become aware of their actions. The article presents the application of a three-stage model “I know – I want to know – I learned for the development of critical thinking in the study of the topic “Type of Molluscs” in Biology and Health Education in 7th grade.