Function of yolk sac in human embryos? Forms blood cells shock absorber forms the placenta Nutrition. Which cells allow embryos to implant in the Uterus? Syncytriophoblast trophoblast E- cadherin\'s goner cell mass Solution Option D. Yolk sac is responsible for the process of viteline circulation in which it provides nutrition to the developing embryo through the primitive aorta. 2. Option B. As trophoblasts are the cells which make the placenta. Placenta connects the foetus to the uterine wall which helps in transfer of nutrients etc to the developing foetus..