Germ cells appear in yolk sac at :
As early as the third week of gestation, primordial germ cells appear in the endoderm of yolk sac, and these migrate along the dorsal mesentry to the urogenital ridge by the eighth week Reference: Shaw's textbook of Gynaecology 15th edition page 27
3 weeks
6 weeks
9 weeks
5 weeks
General obstetrics