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Conception
Fertilization occurs when a sperm meets and penetrates an egg. This process is also called fertilization. -
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The First Trimester
Watch what happens during the First Trimester
The first trimester is when all of the organs, nerves, and brain cells develop -
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Period of the Zygote
Watch this Period of the Zygote Animation
The Period of the Zygote begins at conception and ends when the fertilized egg implants in the mother's uterus. This period can last from 10 to 14 days.
