When does the soul enter the body in the case of identical twins?

I know that a living human being is created at conception. But what about when a fertilized egg splits in the case of monozygotic/identical twins (or more)? Biologically speaking, the zygote exists for about 4-5 days and the next phase of human development is when the zygote gives way to the blastocyst. This forming of the blastocyst is usually where the split takes place, 4-5 days after conception. It is still unclear to doctors today exactly why zygotes split.

Do you think that once the sperm and egg unite the cell is genetically programmed to split into 2 embryos? Is the cell given two separate souls at conception even though the separate bodies will not become evident for several more days?

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**Recommended Reading:
*]When do people get their souls?
*]How can embryos be human when identical twins separate days after fertilization?

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