Among the signs associated with the X chromosome, one can point to a gene that causes organic phosphorus deficiency in the blood. As a result, in the presence of this gene, rickets often develop that are resistant to treatment with conventional doses of vitamin D. In the marriages of nine sick women with healthy men, half of the sick girls and half of the sick boys were among the children. Determine the genotypes of the parents, the nature of inheritance, and the reason for this splitting of the trait according to genotypes.
1) genotypes of parents XFXf and XfY;
2) genotypes of children XFY, XFXf, XfXf, XfY;
3) the nature of inheritance is dominant, linked to the X chromosome.
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.