Why do red blood cells break down when placed in distilled water?

1) The concentration of substances in red blood cells is higher than in water.
2) Due to the difference in concentration, water enters red blood cells, the volume of red blood cells increases, as a result of which they are destroyed.

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.