WAEC Biology 2010 Theory — Question 15

Model answer

Functions of the human placenta: (i) digested food is absorbed from the mother's blood and passed to the embryo; (ii) it selects what substances are to pass to the embryo's blood; (iii) it exchanges carbon dioxide from the embryo's blood for oxygen from the mother's blood; (iv) it produces hormones that support pregnancy; (v) it acts as a barrier against some harmful substances/pathogens (any five).