What happens when you replace a fertilized egg with a stem cell or skin cell?

What is the significance of removing the fertilized egg? Couldn't you just place a skin cell in the location without having first removed a different cell from that location?

53 minutes ago, zapatos said:

What is the significance of removing the fertilized egg? Couldn't you just place a skin cell in the location without having first removed a different cell from that location?

It is the fertilized egg of a dinosaur @@, so it needs to be placed outside

But sure, if it is a sibling fertilized egg you can keep it next to it without replacing it.

If you want this conversation to go anywhere you are going to have to be a bit more free with the details.

I was trying to compare the structure between a zygote and a stem cell. The idea is when a stem cell is infused with progesterone, it becomes a fetus. The zygote, however, is a package of umbilical cord+fetus because it goes through the blastocyst stage. So I was curious as to know if you could replace the zygote with a stem cell. As for the skin cell it should become a grown man with progesterone, but that is because it is an aged cell to being with.