Answer:
Chromosomes are passed down from parents (eggs and sperm). A specific kind of chromosome contains a gene that determines how the gene is inherited. Each person has two alleles and one is inherited from the mother and the other from the father. There are 46 chromosomes and 23 from each parent mixed around to figure which gene is going to be seen. Each egg carries an X chromosome and each sperm carries an X or Y chromosome and if there is two X chromosomes then it's a baby girl and if it is a X and a Y chromosome it's a boy.