The article describes the methodology of forming the subject competences in biology and ecology in the 10th form at the level using the problem method of teaching. The purpose of this article is to study the didactic possibilities of using the problem approach during the formation of subject competences in high school students during the study of the topic "Plastic exchange". Involving students in the cognitive process by creating a problem situation can contribute to the formation of various subject competences. One of the skills sections is the ability to apply the acquired theoretical knowledge and practical skills in the field of biology and ecology in the execution of tasks, which involves making decisions in variables and non-standard situations. A presentation by a student or a group of students of a joint mini-project at a lesson forms a communicative subject competence – the ability to describe verbally and in writing the facts, it is understandable for the audience to communicate their views on the actual scientific and social problems in the field of biology. If students also use the appropriate technical means, then this will be the achievement of competence – the ability to formulate and argue their own hypotheses using information and communication technologies. When solving problem situations, there is an intensification of thinking, not simply memorization of ready. It contributes to the formation of substantive competence from the sphere of autonomy and responsibility – the ability to independently search and learn new knowledge in the field of biology and ecology, to generate new ideas and defend their own thoughts. The solution of the problem at the level of the plant cell emphasizes the ecological importance of water and sunlight at the level of the biosphere of our planet. Thus, subject competence can be formed – the ability to form a causal relationship between the phenomena of wildlife and human economic activity, their impact on human health and safety.