question_answer

Directions : (11 - 15)

Read the passage given below and answer the following questions.

In co-dominance the \[{{F}_{1}}\] generation resembles both parents. A good example is different types of red blood cells that determine ABO blood grouping in human beings. ABO blood groups are controlled by the gene I. Tie 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 \[{{I}^{A}}\], \[{{I}^{B}}\] and i. The alleles \[{{I}^{A}}\] 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 three I gene alleles.  \[{{I}^{A}}\]and \[{{I}^{B}}\] are completely dominant over in other words when \[{{I}^{A}}\] and \[{{I}^{B}}\] are present only \[{{I}^{A}}\] expresses because i does not produce any sugar and when \[{{I}^{B}}\] and i are present \[{{I}^{B}}\] expresses. But when \[{{I}^{A}}\]and \[{{I}^{B}}\] are present together they both express their own types of sugars: this is because of co-dominance. Hence red blood cells have both A and B types of sugars. Since there are three different alleles, there are six different combinations of these three alleles that are possible a total of six different genotypes of the human ABO blood types.

A good example of codominance is

A) A - ve blood group in human being

B) B - ve blood group in human being

C) AB blood group in human being

D) O blood group in human being