The biological cycle has existed since the appearance of living beings. With its appearance, the biosphere also arose.The cycle of substances is characterized by the presence of four obligatory interrelated components:
1) stock of chemicals and energy (abiotic environment);
As a result, the entire living population of the biosphere and the environment, from where organisms obtain the means they need for life and where they excrete the products of their vital activity, create an open living system – an ecosystem. Organized into a global ecosystem, life on planet Earth has been going on continuously for millions of years.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.