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The Endowment for Human Development
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The Morula and Blastocyst


5 days

From The Biology of Prenatal Development.Buy Now

Script: 到受精后的第3至4天 胚胎分裂的细胞 呈现球形, 胚胎称为桑椹胚。

到第4至5天, 细胞球内形成一个腔, 这时的胚胎称为胚泡.

胚泡内部的细胞 称为内细胞群, 形成发育中的人的头、身体 和其它重要结构。

All ages referenced to fertilization, not last menstrual period.
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Fertilization 2
Fertilization 2
Cell Division
Cell Division
The Morula and Blastocyst
The Morula and Blastocyst
3 Billion Base Pairs per Cell
3 Billion Base Pairs per Cell
Amnion and Germ Layers
Amnion and Germ Layers
Early Embryonic Development
Early Embryonic Development
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