Question

(a) How does the embryo get nourishment inside the mother's body?
​(b) If the blood group of father is A and the blood group of mother is O, what will be the blood group of their daughter? Explain how you have arrived at your answer.

Answer 1

(a) Placenta

1. An embryo gets nourishment inside the mother's body through the placenta.
2. It is a special disc-like organ that develops in the fourth week of pregnancy.
3. It establishes an intimate connection between the fetal membrane and the uterine wall via the umbilical cord.
   

functions of Placenta:

1. The exchange of materials between the blood of the mother and the fetus takes place through the placenta.
2. It provides nutrition to the fetus
3. It also serves as the respiratory (by allowing the exchange of oxygen and carbon dioxide) and excretory organ (by allowing the excretion of waste material of the fetus into the mother's blood) of the fetus.

(b) The blood group of the mother is O which means, it has genotype ii.
The blood group of the father is A which means, he can have the genotype I^AI^A or I^Ai.
Case I: If the genotype of the father's blood group is I^AI^A and the mother is ii.

In this case, the daughter will have blood group A.
Case II: If the genotype of the father's blood group is I^Ai and the mother is ii

In this case, the daughter has 50% chance of having blood group A and 50% chance of having blood group O.