sex refers to the biological and physiological characteristics that define men and women. gender refers to the socially constructed roles, behaviours, activities, and attributes that a given society considers appropriate for men and women. male and female are sex categories, while masculine and feminine are gender categories. External genitalia: testosterone urogenital tubercle > male external genitalia (penis and scrotum) Urogenital sinus > prostate gland: absence of testosterone urogenital tubercle and sinus becomes vagina, labia majora and minor, and clitoris. Prenatal sex selection: inequity prior to birth: national census [and birth registration data] data indicates that in recent decades, sex-ratio imbalances have grown in favour of boys. The trend has shifted geographically over time, beginning in a number of asian countries (china, india, and the republic of korea) in the 1980s, followed by some countries of the caucasus (azerbaijan, armenia and. Georgia) in the 1990s, and has more recently been followed by montenegro, albania, and vietnam.