Sex chromosomes
A baby is to be a girl or a boy is settled at conception.
Ovum only X
Sperm also has X or Y.
When sperm X joins with the ovum, the baby is a girl: 44+XX
When sperm Y joins with the ovum, the baby is a boy: 44+XY
A baby is to be a girl or a boy is settled at conception.
Ovum only X
Sperm also has X or Y.
When sperm X joins with the ovum, the baby is a girl: 44+XX
When sperm Y joins with the ovum, the baby is a boy: 44+XY