<span>The product of fertilization is a one-cell embryo with a diploid complement of chromosomes. Over the next few days, the mammalian embryo undergoes a series of cell divisions, ultimately leading to formation of a hollow sphere of cells known as a blastocyst. At some point between fertilization and blastocyst formation, the embryo moves out of the oviduct, into the lumen of the uterus.The images below demonstrate major transitions in structure during early embryogenesis in cattle. Note that in all of the the early stages, the embryo is encased in its zona pellucida. Embryos from other mammals have a very similar appearance, and the general sequence of stages is seen in all mammals.
</span>
My answer is the Vacoules, but I might be wrong.
Speaking form a Christian perspective, God was never a human, he is a being. His son Jesus on the other hand is half human and half god. I personally believe that God was never made and he has always existed. It makes no sense to us humans since all we've ever known was that everything has a beginning and ending. I think there is more to our universe than we are capable of understanding.