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The Endowment for Human Development
The Endowment for Human Development
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Slideshow: Early Events

Two-Cell Embryo

#41, Slide 4 of 24

36 hours

Source: Centro Riproduzione Assistita, Catania, Italy.

Label Key:

1. zona pellucida
2. perivitelline space
3. blastomere #1
4. blastomere #2
5. cell membrane of blastomere #1
All ages referenced to fertilization, not last menstrual period.
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