Which hormone is primarily responsible for male secondary sexual characteristics?

• A. Estrogen
• B. Testosterone
• C. Progesterone
• D. Insulin

Answer: (B)

Testosterone is the hormone that primarily drives male secondary sexual characteristics. It’s mainly produced in the testes under the control of luteinizing hormone from the pituitary. When testosterone rises during puberty, it triggers the development of features such as facial and body hair, a deeper voice, increased muscle mass, and growth of the penis and testes. It also promotes sperm production in the testes with support from FSH.

Some testosterone is converted to estrogen by the enzyme aromatase, and that estrogen helps with bone maturation and the eventual closure of growth plates, but the visible puberty-related changes in males are driven mainly by testosterone itself. Estrogen is the key hormone for female secondary sexual characteristics, and while males have small amounts of estrogen, it does not drive male puberty. Progesterone is primarily involved in female reproductive processes, and insulin regulates metabolism rather than sexual development.