Question

Which of the following genotype does not produce any sugar polymer on the surface of the $RBC$?

• A. $I^{A} \, I^{A}$
• B. $I^{b}i$
• C. $I^{A}\,I^{B}$
• D. $i\, i$
• E. $I^{B}\, I^{B}$

Answer 1

Answer: (D)

The plasma membrane of the red blood cells has sugar polymers that protrude from its surface and the kind of sugar is controlled by the gene. 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.