(i) Implantation: The zygote when fixes itself on the inner thick wall of uterus for further development is called implantation.
(ii) Placenta: It is the special tissue in the form of a disc which is embedded in the uterus wall. It provides large surface area for glucose and oxygen to pass from mother to the embryo. The waste generated by the embryo also passes into the mother’s blood through this placenta
