________ causes changes in appearance seen in boys at time of puberty.

The correct answer is Testosterone.

• Testosterone causes changes in the appearance seen in boys at the time of puberty.
• Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction.

Key Points

• For guys, these hormones travel through the blood and give the testes the signal to begin the production of testosterone and sperm.
• Testosterone is the hormone that causes most of the changes in a guy's body during puberty.
• Sex hormones are chemical substances produced by sex organs.
  • For example, Testosterone is the male sex hormone produced by the testis, and estrogen is the female sex hormone produced by the ovary. These hormones affect the sexual features of an organism.

Additional Information

• Functions of sex hormones:
  • Testosterone: This hormone brings about secondary sex characters in boys such as the growth of a beard, the voice becoming hoarse, development of reproductive organs, etc.
  • Oestrogen: This hormone is responsible for the development of secondary sexual characters in females such as the enlargement of breasts, development of female reproductive organs, etc.

Important Points