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

The Calm Before the Storm

#362, Slide 1 of 24

From The Biology of Prenatal Development.Buy Now

Label Key:

1. zona pellucida
2. spermatozoa
3. oocyte
All ages referenced to fertilization, not last menstrual period.
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