What is the initial cell that contains the genetic information of both parents?

The embryo refers to the developing stage after the zygote has begun to divide and differentiate, typically from the second week to the end of the eighth week after fertilization. While it contains genetic information from both parents, it is not the initial cell itself but rather a later stage of development.

The trophoblast is a layer of cells that forms part of the blastocyst, which is involved in the implantation of the embryo into the uterine wall and nutrient exchange. It does not contain the combined genetic information of both parents but is instead derived from the zygote.

The blastocyst is a structure formed from the zygote after several rounds of cell division, characterized by a fluid-filled cavity and a group of cells that will develop into the embryo. While it is a crucial stage in development, it is not the initial cell that contains the genetic information from both parents.