Transcribed from the July 10, 2017 Twitter thread.
Biological sex is composed of chromosomal sex (genotype, XX/Xy/var), endocrinologic sex (which helps make the secondary sex characteristics), gonadal sex (gonads), sex hormones, and morphological sex just to name a few components. Biological sex includes chromosomes (XX/Xy/var) (genotype), endocrine levels, gonads, sex hormones, external genitals, and secondary sex characteristics. Of these, the only one we currently CANNOT change is the chromosome (genotype) portion.
However, no one except the people against trans people make the claim that trans people can change their chromosomes. So if you’re going to use “biological sex” as your justification for your attacks on transgender and intersex people, just shut up, OK? Because what you’re trying to use is CHROMOSOMAL SEX which is only a fraction of biological sex, and as such shows just how ignorant you are.