Identify the wrong statement with reference to the gene 'I' that controls ABO blood groups.
Answer: (A) When IA and IB are present together, they express same type of sugar. Answer: (A) When IA and IB are present together, they express same type of sugar Solution: This is the wrong statement.
- A.When IA and IB are present together, they express same type of sugar✓
- B.Allele 'i' does not produce any sugar
- C.The gene (I) has three alleles
- D.A person will have only two of the three alleles
Correct Answer
(A) When IA and IB are present together, they express same type of sugar
Solution & Explanation
Answer: (A) When IA and IB are present together, they express same type of sugar Solution: This is the wrong statement. When IA and IB are present together, they each express their OWN (different) type of sugar due to co-dominance, so the RBCs carry both A and B sugars, not the same sugar. The other statements are correct: i produces no sugar, the gene I has three alleles, and being diploid a person carries only two of the three alleles. NCERT Reference: NCERT Class XII, Ch 4, p.61, lines 026-028: "But when IA and IB are present together they both express their own types of sugars: this is because of co-dominance. Hence red blood cells have both A and B types of sugars."