When would exposure to a potentially harmful substance be most likely to damage many organs in a developing embryo?
(1)during the last three months of pregnancy
(2)during the early stages of pregnancy
(3)during the formation of the zygote
(4)during meiosis in both males and females
(1)during the last three months of pregnancy
(2)during the early stages of pregnancy
(3)during the formation of the zygote
(4)during meiosis in both males and females