What a clear explanation, I really got many things home here tonight. May Allah bless our doctor and grant him a long life filled with KHAYR. To everyone reading and listening, please understand clearly what the doctor said: He meant that the female is the determinant of sex. Every female has XX chromosomes, while males have XY chromosomes. So, when an X chromosome from the mother pairs with an X chromosome from the father, the child will be female (XX). If the X chromosome from the mother pairs with a Y chromosome from the father, the child will be male (XY).