All the physical changes during puberty that leads to formation of gametes is due to hormones only...
Hormonal changes are
1. Level of testosterone increases in male
2. Androgens sythesis starts for the devleopment of sperms
3. Progesterone level increase in females
4. Estrogen level increases that leads to the devleopment of graffian follicels..
Devlopment of beard, Adams apple , internal hair's, deepening of voice
Mensturation begins, armpit and internal hair's,enlargement of breast