Question

If three children in a family have blood groups O, AB and A, the genotypes of the parents must be _____ and ____ .

Answer 1

Answer:

ANSWER

Human blood group inheritance is governed by three alleles namely I  

A

, I  

B

 and i. I  

A

 and I  

B

 show codominance while allele "i" is recessive to both "I  

A

" and "I  

B

". Therefore, children with A blood group have atleast one I  

A

 allele but no I  

B

 allele while those with B blood group have atleast one I  

B

 allele but no I  

A

 allele. Similarly, children with AB blood group will have one copy of each I  

A

 and I  

B

 allele. Option A is correct as the children with A, B and AB blood group are produced. Another child with O blood group can be produced along with these children as there is presence of i allele in both parents.  

Thus, the correct answer is option A.

Explanation: