Zoology - Principles of Inheritance and Variation Question with Solution | TestHub

ABO blood group in humans is controlled by gene I and shows co-dominance. The gene I has three alleles${\mathrm{I}}^{\mathrm{A}}, {\mathrm{I}}^{\mathrm{B}}$and i.${\mathrm{I}}^{\mathrm{A}}$and${\mathrm{I}}^{\mathrm{B}}$produce slightly different form of sugar, while allele i does not produce any sugar.${\mathrm{I}}^{\mathrm{A}}$and${\mathrm{I}}^{\mathrm{B}}$are completely dominant over allele i. But if${\mathrm{I}}^{\mathrm{A}}$and${\mathrm{I}}^{\mathrm{B}}$are present together, they both express their own types of sugars.