Respuesta :
A human has 46 chromosome pairs. For a baby to be a boy its needs to have a xy chromosome and for it to be a girl it has to be xx.
Humans have a total of 46 chromosomes or 23 pairs. A baby's gender is determined by its x and y chromosomes if its double x then it's a female if its an x and a y it's a male. The father determines all this since he's the one that holds the y.