XY sex-determination system - Wikipedia In the XY sex-determination system, the female-provided ovum contributes an X chromosome and the male-provided sperm contributes either an X chromosome or a Y chromosome, resulting in female (XX) or male (XY) offspring, respectively
XY Official Website XYは、日本テレビ系オーディション番組「YOSHIKI SUPERSTAR PROJECT X」から誕生した13人組の変幻自在なボーイズバンド。