I know that for a given mammal, half the chromosomes come from father and half from mother. This is typically denoted as x-y. I've recently read about "toolkit" genes that control how a cell develops into an embryo into an organism. I'm interested which set of chromosomes(x,y or both) contains these toolkit genes for development of an organism from a fertilized cell?
In other words, does an X chromosome know how to build a female and Y chromosome how to build a male, or is it some "overriding" of developmental instructions that Takes place when Y is present?