What is the biological meaning of mitosis and meiosis?

The biological significance of mitosis is an increase in the number of cells, the growth of the body. Also, mitosis provides vegetative propagation and regeneration.
Meiosis underlies the formation of germ cells (gametes). Provides the possibility of sexual reproduction and variability of offspring.

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.