ZWの存在を知らなかったのでXとYって見た目の話じゃなかったんだという気づきを得てる
なるほどなぁ
The idea that the X chromosome was named after its similarity to the letter "X" is mistaken. All chromosomes normally appear as an amorphous blob under the microscope and take on a well-defined shape only during mitosis. This shape is vaguely X-shaped for all chromosomes. It is entirely coincidental that the Y chromosome, during mitosis, has two very short branches which can look merged under the microscope and appear as the descender of a Y-shape.[^6]
[^6]: Bainbridge, pages 65-66
https://en.wikipedia.org/wiki/X_chromosome