Answer
The difference between them is that, sex refers to “the different biological and physiological characteristics of males and females, such as reproductive organs, chromosomes, hormones, etc.” While gender refers to "the socially constructed characteristics of women and men – such as norms, roles and relationships of and between groups of women and men.
Opinion Like Answer
There's alots of difference between sex and gender. But I think the main difference is that sex is assigned at birth, while gender is how a person identifies. It's difference is determined by my physical body and culture by having seen it their self if I or people like me, belongs to the former or latter, or both. (They can see it just by taking a glance at somebody's appearance or just confirming it themselves by asking politely.)
