Arguments that treat biology as fundamental have done their bit in ensuring that women have always had to work along the grain, what with all the legislators, priests, philosophers, writers and scientists who have striven to show that not only is the subordinate position of women a divine doing but moreover is advantageous and honorable. Breaking the stronghold of this idea that 'a woman's body is her destiny' is imperative if the goal modern society wishes to reach is a true equality of the sexes. Otherwise, all attempts to question the attributed sex roles will fly in the face of 'natural order'. It is therefore useful to distinguish between the concepts of sex and gender. Sex is defined as biological differences in genetic composition and reproductive anatomy and function.
All mammalian species have two biological forms - female and male.
Human infants are labeled as one sex or the other at birth, based on the appearance of their genitals. Gender is what culture makes out of the 'raw material' of biological sex. All known societies recognize biological differentiation and use it as a basis for social distinctions and the process of creating gendered human beings starts at birth. When a baby is born, the presence of a vagina or penis represents sex - but the blue or pink blanket that enfolds the baby represents gender. The blanket serves as a cue that this human is to be treated as a boy or a girl, not as a 'generic human' from the start.