Blood from the fetus circulates through the placenta.
a) What substances pass (i) from the maternal to the fetal blood, (ii) from the fetal to the maternal blood?
b) By what means is the fetal blood circulated through the placenta?
a) (i) oxygen and digested food (glucose, amino acids) going from maternal to fetal blood,
(ii) carbon dioxide and nitrogenous waste (urea) going from fetal to maternal blood.
(b) The fetus's own heart pumps blood by the fetal vessels in the placenta.