Concentration of which of the following substances will decrease in the maternal blood as it flows from embryo to placenta through the umbilical cord?

The Human foetus within the uterus
(I) Oxygen
(II) Amino Acids
(III) Carbon dioxide
(IV) Urea

Options

A. (I) and (II)
B. (II) and (IV)
C. (III) and (IV)
D. (I) and (IV)

Answer

A

Explanation

Placenta ensures nutrient and Oxygen supply to the embryo. The blood returning to placenta won.t have Oxygen and nutrients Amino acids) as they would have been consumed by the foetus. Instead, Carbon dioxide and other waste materials form the fonts will be present in it as placenta also acts as a facilitator to remove waste products from the foetus.