CK-12 Foundation
Ck 12: Life Science: Pregnancy and Childbirth
[Free Registration/Login may be required to access all resource tools.] While a woman is pregnant, the developing baby may be called an embryo or a fetus. The embryo stage lasts until the end of the 8th week after fertilization. After...
CK-12 Foundation
Ck 12: Biology: Fetal Development and the Placenta
[Free Registration/Login may be required to access all resource tools.] Discusses the role of the placenta during fetal development.