/----/ XX and XY chromosomes. You can pretend to change, but can't really do it. That's the science.Chromosomes determine sex, not gender. Learn the science so you can trust it
Now trust the dictionary: The American Heritage® Dictionary of the English Language, 5th Edition
gender /jĕn′dər/
noun
- A grammatical category, often designated as male, female, or neuter, used in the classification of nouns, pronouns, adjectives, and, in some languages, verbs that may be arbitrary or based on characteristics such as sex or animacy and that determines agreement with or selection of modifiers, referents, or grammatical forms.
- The fact of being classified as belonging to such a category.
"agreement in gender, number, and case." - Either of the two divisions, designated female and male, by which most organisms are classified on the basis of their reproductive organs and functions; sex.