What is Codominance

Codominance is an inheritance pattern in which both of the alleles of a particular gene in a diploid organism are expressed in the organism’s phenotype. This type of inheritance occurs in plants, animals and humans alike. It is most commonly seen in plants, where the different alleles for a given trait can be expressed simultaneously. Codominance is in contrast to dominance, where one allele completely masks the expression of the other, or recessiveness, where the expression of a trait is dependent on the presence of two identical alleles.

Examples of Codominance

Codominance can be observed in humans in certain blood types. For example, A and B blood types are both codominant. An individual who is A/B (has one A and one B allele) will have both A and B antigens expressed, rather than just one or the other. This is due to the fact that the enzymes needed to construct each antigen are both produced and therefore, both antigens are present on the surface of the red blood cells.

Another example of codominance in humans can be seen in the AB blood type, which is a combination of both A and B antigens. This is due to the fact that both antigens are present in the same cell, giving the red blood cells both antigens.

In animals, codominance can be observed in color traits. One example is in chickens, where a trait such as feather color can be codominant. For example, a chicken that has both a red and a white feather, will have a phenotype that is a mix of both the red and the white color.

Explaining Codominance

Codominance occurs when both alleles of a gene are expressed, rather than just one or the other. This means that, due to different genetic instructions, both alleles can be expressed in the phenotype of the organism. In contrast to dominant and recessive patterns of inheritance, codominance results in a combination of traits that are different from both of the individuals that were used to produce them.

In codominance, the phenotype will always be a combination of both of the alleles that are present. For example, an individual who is A/B in their blood type will have a phenotype that is a combination of both the A and the B antigens. This is because both of the enzymes that are needed to construct both the A and B antigens are produced. This then results in the individual having both A and B antigens present on the surface of the red blood cells.

Conclusion

Codominance is a type of inheritance where both of the alleles for a given gene in a diploid organism are expressed in the organism’s phenotype. It is most commonly seen in plants, animals and humans. Examples of codominance in humans can be seen in certain blood types, such as A/B or AB. Codominance occurs when both alleles of a gene are expressed, rather than just one or the other. This results in the phenotype being a combination of both of the alleles that are present.