Primary sex characteristic - Definition and Overview

Primary sex characteristic

In biology and medicine, primary sex characteristics are those differences in male and female anatomy which are present at birth. Secondary sex characteristics are those differences which appear at puberty (or reproductive maturity). Primary sex characteristics may be sex dimorphic (e.g., size of phallus) or sex dichotomous (e.g., presence or absence of uterus).

See sexual differentiation, sexual dimorphism.