С The placenta acts as a barrier keeping the blood of the mother and the fetus separate.

i. Suggest why the blood of the mother is separated from the blood of the fetus.

ii. Despite the barrier between the maternal and fetal blood systems, some harmful
chemical substances may pass from the mother to the fetus.
Suggest one example.
D. After it is born, the baby's main source of food is milk.
Give two advantages of feeding a baby on breast milk rather than using milk
prepared from milk powder.