Question

Explain the genetic basis of blood grouping in the human population. [5]

Answer 1

The blood group of an individual is determined by the I gene. The plasma membrane of RBCs have sugar polymers. The kind of sugar is controlled by the gene I which has three alleles $I^A,I^B$ and i. The alleles $I^A\mathrm{and}{I}^B$ produce a slightly different form of the sugar while allele i doesn’t produce any sugar. Because humans are diploid organisms, each person possesses any two of the I gene alleles. [3]
The blood group of any individual can be determined by the following table: [2]