Question

A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits-blood group A or 0 -is dominant? Why or why not?​

Answer 1

Explanation:

The given information is not enough to determine the traits- blood group A or O is dominant.

In ABO blood grouping blood type A is always dominant whereas, the blood type O is always recessive.

Here the father's blood group is A hence, it can either be homozygous (AA) or heterozygous (AO).

The mother's blood group is O and it is only possible if it is heterozygous (OO).

For the daughter to have blood group O the father must be heterozygous (AO) and mother must be (OO).

Answer 2

|$\large\mathrm\green{Solution}$|

Given information is not enough to tell us which characteristics are dominant –blood group A or O. Blood type A is always dominant in the type of ABO blood and blood type O is always recessive. Here, father’s group of blood may be genotypically AA (homozygous) or AO (heterozygous), where as that of mother can be OA or OO.