Sex hormones play key roles in both secondary sex characteristics and reproductive processes. In males, testosterone promotes the development of facial and body hair, deepening of the voice, and muscle growth. In females, estradiol contributes to breast development, wider hips, and the menstrual cycle, while progesterone regulates the menstrual cycle and prepares the uterus for pregnancy. In reproductive processes, testosterone supports sperm production in males, while estradiol and progesterone regulate the menstrual cycle, facilitate ovulation, and maintain the uterine lining for potential pregnancy in females. These hormones collectively influence the development and functioning of the reproductive system.