Human reproduction - Weebly

3.5 weeks CNS begins to develop, heart forms and starts to beat, blood vessels form. 4 weeks Embryo 0.5 cm long. Arm and leg buds visible, umbilical cord (5-6mm) forms, tail visible. 5 weeks Embryo 1.25 cm long. All internal organs, i.e. liver, kidney, lungs and sex organs, have begun to form. 6 weeks Eyes visible, nose and ears forming, arms ... ................
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