Question

Person having genotype $I^A$, $I^B$ would show the blood group as AB. This is because of:

• A. Codominance
  
• B. Segregation
  
• C. Pleiotropy
• D. Incomplete dominance
  

Answer 1

The correct option is A Codominance


Blood group:

Blood group refers to any of the various types of human blood whose characteristics of antigen on the cell determine compatibility in transfusion.

ABO blood group system:

Codominance:

I gene have three alleles $I^A$, $I^B$ and $I^O$. $I^A$ and $I^B$ are dominant to $I^O$. However, the expression of $I^A$, $I^B$ don't follow the dominant-recessive phenotype. Hence, a person having$I^A$ and $I^B$ has AB blood group. The pattern of inheritance when the alleles of a gene pair are expressed together in the offspring without following dominant-recessive relationship is referred to as codominance.

Pleiotropy :

Pleiotropy is a genetic condition when a single gene influences two or more distinct phenotypic characteristics or traits.

Segregation :

Segregation refers to separation or moving apart. Alleles of a gene segregate due to the separation of the homologous chromosomes during the gamete formation.

Incomplete dominance:


Incomplete dominance is a pattern of inheritance when the dominant allele is not able to mask the effect of recessive allele completely in a heterozygous condition giving the progeny an intermediate phenotype.

Final answer :
b.) Codominance