[Tiva]

Gender is a social construct, in the US there are only 2 in some places there are as much as 7 different genders. Male, Female, Bisexual, Transexual, Masculine Female, Feminine Male, & Inner sex are the ones I have come across. The Jewish texts have 6 genders mentioned in it.
Sex is your physical placement, if you have a Y chromosome you are of the male sex if you have no Y you are female sex, this is due to markers in the body and skeleton things like your hips, skull and long bones. Muscle attachments also trend to be larger.

That is what I have been taught in my field of study.