Question

A man of blood type AB marries a woman of blood type A. The woman’s mother was blood type O. What are the chances that their children will have blood A?

Answer 1

Answer:

B

Explanation:

Genotype of a heterozygous man with A blood group I  

A

I and that of a homozygous man with A blood group I  

A

I  

A

.  

A cross between heterozygous man with A blood group and woman of AB blood group produce progeny with A, AB and B blood groups.  

Gametes

I  

A

I

I  

A

I  

B

 

I  

A

  I

I  

A

   I  

A

I  

A

   I  

A

I

I  

B

   I  

A

I  

B

 

 I  

B

I

On the other hand, a cross between homozygous man with A blood group, I  

A

I  

A

 and woman of AB blood group, I  

A

I  

B

 produce progeny with A, AB blood groups, none of the child will have B blood group.  

Gametes

I  

A

I  

A

 

I  

A

I  

B

 

I  

A

 I  

A

 

I  

A

   I  

A

I  

A

   I  

A

I  

A

 

I  

B

  I  

A

I  

B

 

 I  

A

I  

B

 

Hence, a child with B blood group would indicate that man is heterozygous A.