The organ made from both tissue of the embryo and the mother is the placenta.

Here's why:

* Embryonic Contribution: The placenta develops from the chorion, a membrane that surrounds the embryo. This chorion forms the fetal portion of the placenta.

* Maternal Contribution: The placenta also develops from the endometrium, the lining of the mother's uterus. This endometrium forms the maternal portion of the placenta.

The placenta acts as a vital interface between the developing fetus and the mother, allowing for the exchange of nutrients, oxygen, and waste products.