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Prenatal Development
§At 9 weeks an embryo turns into a fetus (c and d). Teratogens are chemicals or viruses that can enter the placenta and harm the developing fetus.
Text Box: Lennart Nilsson/ Albert Bonniers Publishing Company
Lennart Nilsson/ Albert Bonniers Publishing Company
Text Box: Lennart Nilsson/ Albert Bonniers Publishing Company
Lennart Nilsson/ Albert Bonniers Publishing Company