(N/A) Placenta: It is a specialized structural and functional unit that connects the developing embryo to the uterine wall of the mother.
Structure: It is a disc-like tissue embedded in the uterine wall. On the embryo's side,it possesses finger-like projections called villi. On the mother's side,there are blood spaces (lacunae) that surround these villi,allowing for the exchange of materials.
Functions:
$1$. It provides a large surface area for the transfer of nutrients like glucose and respiratory gases like oxygen from the mother's blood to the embryo.
$2$. It facilitates the removal of metabolic waste products and carbon dioxide produced by the developing embryo by transferring them into the mother's blood.