Answer: Uterus.
Explanation: The male and female gamete fuse to form embryo. The process of fusion of male and female gamete is called as fertilization.
The formed embryo is then transferred to the uterus for implantation and then till 37 weeks of gestation the embryo grows in the uterus.
All the nutrition are transferred to the embryo by the placenta that is an attachment between the mother and embryo.
This is how a embryo in the uterus develops into a child in the embryo.