It used to be thought that those sex-determining chromosomes pictured here -- XY if you're male, XX if you're female -- merely determined whether you would be born with ovaries or testes, and it was the sex hormones that those organs produced that were responsible for the differences we see in the opposite sex.
过去我们常认为 照片中的性染色体—— 男性是XY，女性是XX—— 只会决定你会有卵巢还是睾丸， 而这些器官产生的性激素 是我们看到的异性区别的原因。