Puberty and adolescence are results of the activities of testosterone in males and oestrogen in females. In males during puberty, testosterone secretion is increased resulting in the development of male sex organs and male characters such as deeper voice, moustache, beard and more body hair.
Similarly, in females, oestrogen secretion is increased at the time of puberty resulting in the development of female sex organs and female characters such as feminine voice, soft skin and mammary glands.