Is a biological category determined by the anatomical and physiological characteristics distinguishing male and female. It is defined by a unique combination of chromosomes, hormones, internal reproductive organs and external genitalia.

The word ‘sex’ only refers to someone’s biological inheritance as a man or a woman. Human life is biologically binary by its nature, in the same way that no two males or females experience or express their biological sex in exactly the same way.

Intersex

“Strictly speaking, ‘intersex’ refers to persons born with indeterminate biological sex characteristics (i.e. chromosomes, hormones, internal reproductive organs, external genitalia and/or secondary sexual characteristics) such that it is difficult or impossible to know, on sight, whether an individual is biologically male or female. Often a genetic test is required. There are several recognised medical conditions that qualify as ‘intersex’. 

In our Christian vision we are careful to note that intersex conditions are medical in nature, not psychological.” (acc. Australian Catholic Bishops Conference Created and Loved: A guide for Catholic schools on identity and gender))