Not _quite_, although it's a fairly pedantic technical distinction. As I understand it, an organism that reproduces sexually (rather than asexually) has a sex

Not _quite_, although it's a fairly pedantic technical distinction. As I understand it, an organism that reproduces sexually (rather than asexually) has a sex dependent on the gamete it produces. There _might_ be some insects with more than two sexes[1], but generally a dioecious (two-sexed) species will be anisogamous, meaning one sex is responsible for bringing a load of smaller, simpler gametes (sperm, pollen) to the party whilst the other brings a single, larger one (egg, ova). Put them together and babies happen. The mechanism that determines the organism's sex varies by species. Homo sapiens are a species that have an XY sex-differentiation system. As a sexually dimorhic species (our two sexes look different), one's chromosomes also cause one to express distinct secondary sexual characteristics (e.g., male facial hair, female breasts). Man boobs and bearded women exist, however, so these characteristics are not a 100% accurate indication of one's sex. Also, as another reply stated, the meaning of ‘gender’ may or may not == that of ‘sex’. Gender referred only to a linguistic concept or was a synonym for sex until the '60s-'70s, when radical feminists and sexologists like John Money[2] proposed that gender be used to refer to the expectations, roles and responsibilities that a culture assigns based on sex (i.e., women should raise kids, men are more aggressive). Personally, I feel a term like ‘tertiary’ or ‘socio-sexual characteristics’ would have been a better, less confusing choice, but unfortunately I wasn't around in the '60s to tell them. Outside of social sciences, the words generally remain synonymous. Within social sciences the '60s-'70s-era distinction is retained and gender is studied almost exclusively (as you might expect of a sociological concept rather than a biological one). [1] https://www.sciencedirect.com/science/article/pii/S016953470300315X https://www.sciencedirect.com/science/article/pii/S016953470... [2] https://en.wikipedia.org/wiki/John_Money https://en.wikipedia.org/wiki/John_Money