The article examines issues related to organizing the teaching of the course “Fundamentals of Ecology” in higher education institutions under conditions of interdisciplinary integration, using tasks applied in international assessment studies (PISA-type tasks). The content, structure, and practical effectiveness of a methodological system based on integrating ecology with biology, chemistry, geography, and the social sciences are described. The results of the experimental study demonstrated positive changes in students’ natural science literacy, their ecological thinking, and competencies in analyzing problem situations and making decisions.