Why is a living cell called an open system?

1) a system is a set of components that interact and form a single whole; a cell is a collection of various organelles that interact with each other;
2) a cell is an open system, since an influx of substances, energy and information from outside is required for its normal life.

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.