Which of the following characteristics represent 'Inheritance of blood groups' in humans? a. Dominance b. Co-dominance c. Multiple allele d. Incomplete dominance e. Polygenic inheritance
Answer: (B) a, b and c. Answer: (B) a, b and c Solution: Inheritance of ABO blood groups in humans illustrates dominance (IA and IB are each completely dominant over i), co-dominance (when IA and IB are together both express their own sugars), and multiple alleles (the gene I has three alleles IA, IB and i).
- A.b, d and e
- B.a, b and c✓
- C.b, c and e
- D.a, c and e
Correct Answer
(B) a, b and c
Solution & Explanation
Answer: (B) a, b and c Solution: Inheritance of ABO blood groups in humans illustrates dominance (IA and IB are each completely dominant over i), co-dominance (when IA and IB are together both express their own sugars), and multiple alleles (the gene I has three alleles IA, IB and i). It does NOT show incomplete dominance or polygenic inheritance, so options d and e are excluded; hence a, b and c is correct. NCERT Reference: NCERT Class XII, Ch 4, p.61, lines 020-027: "The gene (I) has three alleles IA, IB and i. The alleles IA and IB produce a slightly different form of the sugar while allele i does not produce any sugar... IA and IB are completely dominant over i... But when IA and IB are present together they both express their own types of sugars: this is because of co-dominance."