A 28-year-old pregnant lady goes to a gynecologist for a check-up. Her doctor explains that there is normal growth of the foetus and the placenta is functioning well.
Mention one function of the placenta.
Topic: Functions of the placenta
Answer
The placenta allows the EXCHANGE OF MATERIALS between the mother and the foetus — oxygen and nutrients pass from the mother’s blood to the foetus, and carbon dioxide and nitrogenous wastes pass back from the foetus to the mother. (Also acceptable: it secretes hormones such as progesterone and oestrogen to maintain pregnancy; it acts as a barrier against certain germs.)
Only ONE function is asked for, so give one and give it fully.
THE POINT MOST OFTEN MISSED: the blood of the mother and that of the foetus DO NOT MIX. They flow close together in the placenta, separated by a thin membrane, and substances pass across it by diffusion. Saying "the mother’s blood goes to the baby" is wrong and examiners look for it.
The placenta is remarkable for doing several jobs at once — it serves as the foetus’s lungs, its digestive system, its kidneys and an endocrine gland, because none of the foetus’s own organs is yet working.