WEBVTT

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Each of us began our journey of life as a single-cell zygote—

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the product of the fusion of the genetic material from our father’s sperm cell and our mother’s ovum.

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This activity tells the story of the first step in the journey of life—the phases of development between conception and birth.

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During the first 2 weeks—the germinal phase of prenatal development—the single cell becomes a mass of cells,

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doubling again and again as it moves down the fallopian tube before implanting in the wall of the mother’s uterus.

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During weeks 3 through 8—the embryonic phase—the mass of cells begins to draw nutrients from the mother’s blood,

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and each organ system begins to form.