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 o – is dominant? why or why not?meritnation

Answer 1

I think it is not sufficient to tell through this example which one is dominant because if the alleles are considered than it is found that the O is recessive as compared to A and B so if phenotypically and Genotypically the offspring is considered then A should be the blood group present in the offspring
But since the offspring has O blood group she is not the member of 1st generation
That means that she is either the second or third daughter
understood!!

Answer 2

No ,this information is not sufficient to tell whether blood group A or O is dominant or recessive .

Explanation:

Possible bloodgroups of man-AA ,AO

possible || of woman-OO

The above given information firstly laks genitic information of pairs here

Let again assume two cases

1..mans bloodgroup AA

crossing ..AO for all progeny

but it is not possible because the bloodgroup of their daughter is O

therefore the bloodgroup of the man is

AO

2 case....

man bloodgroup AO

woman OO

crossing outcomes

1.AO

2.AO

3.OO

4.OO

therefore bothe bloodgrops have equal chance ,therefore we cant judge which on is dominant or recessive.

Hope the self handwritten ans will help my companions