Hi ,
This idea came in my mind and I realized I don't have an answer for it . Maybe it is simple but anyway I will ask :
How is it that when identic twins are conceived , if they will be boy and girl ,the girl's brain will be altered by estrogen and the boy's brain will be masculinized by testosterone . I am not sure , but I thought they would share everything (like blood , including hormones : type and concentration ) inside their mom .