Key learning points

1. A zygote divides to become an embryo, which then develops into a foetus made of different cells and tissues.
2. The human gestation period is about 40 weeks.
3. The foetus grows in an amniotic sac which is filled with amniotic fluid for protection.
4. The mother provides all the nutrients that the growing foetus needs and gets rid of waste products through the placenta.
5. During birth, the cervix opens and the uterus wall contracts to push the baby out through the vagina.

Common misconception

Keywords

• Foetus - The foetus is the stage of human development between an embryo (at around 8 weeks) up to when the baby is born.

• Umbilical cord - The umbilical cord joins the placenta to the foetus. It carries the nutrients and oxygen needed from the mother.

• Contractions - Waves of muscle contractions in the uterus wall during childbirth push the baby down through the vagina.

• Placenta - The placenta is an organ that is attached to the uterus wall; it provides the foetus with oxygen and nutrients from the mother's blood.

• Amniotic sac - The amniotic sac surrounds the foetus and contains fluid which protects it.