Why, in some cases, the descendants are completely similar to their parents, while in others they are noticeably different?

An organism that has chromosomes from two parents of different sexes may have similar characteristics to the parents. In some cases, new signs may appear due to the formation of a new combination of hereditary information.

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.