Girl trapped by horrible monsters who fucked her hard Sex usually refers to the characteristics and traits of biological sex. Sex refers especially to physical and biological traits, whereas gender refers especially to social or cultural traits. Sex may also refer to the physiological and psychological processes related to procreation and sexual pleasure. Sex refers to a set of biological attributes in humans and . It is primarily associated with physical and physiological features including chromosomes, gene expression, hormone levels and function, and reproductive/sexual anatomy.