The sex hormones,_______________________ and estrogen are responsible for the development of __________ characters.

Sex hormones:

1. Testosterone is produced by interstitial cells (Leydig cells) of testes in males.
2. A small quantity is produced by adrenal glands.
3. In females, a small quantity of testosterone is produced by both ovaries and adrenal glands.
4. The main function of testosterone is the development of male reproductive tissues and promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of facial hair.
5. Estrogen is produced by the ovaries, adrenal glands, and fat tissues.
6. Females secrete more of this hormone. Estrogen helps to develop secondary sexual characteristics in females such as breast development, menstrual cycle, endometrium, etc.

Thus, the sex hormones, testosterone and estrogen are responsible for the development of secondary sexual characters.