Protection and Development of the Fetus during Pregnancy

Reference to Surah An-Nahl (Q. 16:78): "And Allah has extracted you from the wombs of your mothers not knowing a thing, and He made for you hearing and vision and intellect that perhaps you would be grateful."
There are $3$ layers that surround and protect the foetus during development.

Uterus (Womb): The place that feeds and shelters the baby.
Amniotic Sac (Amnion): A bag of fluid that surrounds the embryo after it implants into the uterus lining.
Amniotic Fluid: Acts as a shock absorber to protect the fetus from bumps and supports the baby as it grows and moves.
Abdominal muscle wall: Provides an additional external layer of protection.
Cervix: A ring of muscle at the entrance of the uterus which widens to allow the baby to pass through during birth.
Vagina: The passage through which the baby is pushed out of the body.

Placenta: A plate-shaped organ attached to the uterus lining that acts as a protective barrier against most infections.
Umbilical Cord: Joins the fetus to the placenta and carries blood containing nutrients and waste.
Blood Separation: The mother's blood and the fetus' blood do not mix. This is because the mother's blood is pumped at a much higher pressure, which would damage the delicate fetus.

Diffusion: Dissolved molecules move between the mother's blood and the fetus' blood across the placenta without mixing.
Substances Provided to Fetus: Oxygen ( $O_2$ ), dissolved food molecules (nutrients), and water ( $H_2O$ ).
Waste Removed from Fetus: Carbon dioxide ( $CO_2$ ) and urea.
Respiration: A foetus cannot breathe air until birth; all oxygen is supplied via the mother's blood through the umbilical cord.

If a fertilised egg cell just kept dividing, it would make a big round blob of identical cells. Describe what else must happen as the embryo develops and becomes a fetus: Cells must differentiate and specialize to form different tissues and organs.
At what stage of development does the heart start beating? The heart begins beating during the early embryonic stage.
State two functions of the bag of fluid that forms around the fetus in the uterus: It acts as a shock absorber to protect from bumps and supports movement/growth.
Produce a flow diagram showing the stages of human development from the fertilised egg to birth: Fertilised egg $\rightarrow$ Embryo $\rightarrow$ Fetus $\rightarrow$ Birth.
Explain how the uterus and placenta support the development of a baby throughout pregnancy: The uterus provides shelter and space, while the placenta facilitates the exchange of oxygen, food, and waste removal while providing a barrier against infection.