Mitosis begins with shortening chromosomes. It occurs gradually, in several stages. This is the prophase stage. At the beginning of prophase, thin chromatin filaments tangled in a ball, in which individual chromosomes cannot be distinguished, can be seen in a light microscope. Towards the end of prophase, the filaments are significantly shortened and thickened at the same time, while some chromosomes, especially short ones, can be distinguished from the total mass.
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.