And we form a structure that contains two identical cells that are equal size and which have the same exact genetic information. Now, by definition, a zygote only consists of one cell. And as soon as we form these two cells, this is no longer a zygote, but now we refer to it as the developing embryo. So this is a two cell embryo, which is found right about here. Now, following this process, two cells are not enough. We have to produce hundreds of cells.