The most viable are people with sex chromosome abnormalities. Why are trisomy organisms in pairs 1-17 the least viable? Why, in this case, even embryos die at different stages of development?
Because during the formation of organs, organs begin to form incorrectly. Therefore, embryos that do not receive the correct development of the brain die, because they cannot develop normally.
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.