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.
Dulu orang mengira bahwa kromosom penentu jenis kelamin yang di gambar ini -- XY jika pria, XX jika wanita -- hanya menentukan apakah Anda punya ovarium ataus testis, dan hormon seksual yang diproduksi organ tersebutlah yang bertanggung jawab akan perbedaan dengan jenis kelamin yang berbeda.