When a fertilised egg E formed in the oviduct of a human female divides repeatedly to form an embryo, the embryo gets implanted in the thick and soft lining of the uterus. After this a disc-like special tissue T develops between the uterus wall and embryo through which all the requirements of the developing embryo (and foetus) are' met from the mother's body. The embryo is connected to the tissue T through a string like structure S.
What happens to S when the baby is born? Why?