Which system determines sex-specific characteristics?

• A. Reproductive System
• B. Endocrine System
• C. Nervous System
• D. Digestive System

Answer: (A)

Sex-specific characteristics are determined by the reproductive system because it directly forms the organs and structures that define male and female bodies, such as the gonads and external genitalia. This system sets up the primary sex characteristics—the anatomical differences that distinguish the sexes. Hormones from the endocrine system influence secondary sex characteristics during puberty, like body hair and voice changes, but the basic sex-specific anatomy comes from the reproductive system itself. The nervous and digestive systems don’t establish these sex-specific features, and while hormones matter for development, they don’t define the core sex-specific anatomy on their own.