What stage is characterized by the development of primary sex characteristics?

The stage characterized by the development of primary sex characteristics is puberty. This period marks the onset of biological changes that lead to sexual maturity. During puberty, individuals experience significant physical changes, many of which are driven by hormonal changes that prepare the body for reproduction.

For example, in boys, puberty is associated with the growth of the testes and the development of sperm, while girls experience the growth of ovaries and begin their menstrual cycle. These changes are fundamental to the biological understanding of sex characteristics, distinguishing them from secondary sex characteristics, which develop slightly later and include features such as breast development in females and facial hair in males.

Understanding this stage is crucial as it lays the foundation for not only physical development but also influences psychological and social aspects of development. Puberty serves as a critical transition point leading into adolescence, which encompasses a broader range of emotional and social development, but it is during puberty that the primary sex characteristics specifically emerge.