At the time of division, the sex cells are especially sensitive to the action of various harmful factors: radiation, chemicals (alcohol, drugs, poisons, etc.). A dose of radiation that does not cause noticeable changes in the body can lead to significant damage to gametes. Particularly dangerous adverse effects for the eggs. After all, these cells begin to form even in the embryo, and their supply cannot be replenished throughout life. Therefore, with each damaging effect on the eggs, the likelihood of genetic abnormalities in the offspring increases.
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.