Question

Which of the following is best suited for codominance?

• A. Both are recessive
• B. Both are dominant
• C. One is recessive
• D. One is dominant

Answer 1

The correct option is B Both are dominant

When both recessive and dominant traits are expressed in a heterozygous genotype; it is codominance. This means that none of the factor is recessive but both can express themselves irrespective of their presence in homozygous or heterozygous condition. Since, none of the factor is recessive; options A and C are wrong. None of factor is dominant; option D is wrong. Correct option is C. The $I^A$ and $I^B$ alleles of human blood group gene "i" are codominant and show "AB" blood group when present together.