In order to fully understand the meaning of the term codominance, it is necessary, first, to discover its etymological origin. In this case, we can state that it is a word of Latin origin that is the result of the sum of four very well defined parts:
-The prefix "con-", which can be translated as "together" or "everything".
-The verb "dominare", which is synonymous with "having under his power."
-The particle "-nt-", which is used to indicate "agent".
-The suffix "-ia", which is used to indicate "quality".
It is called genotype to the genetic data which, according to its allelic composition, has a certain organism in its deoxyribonucleic acid (DNA ). Allelic , for its part, comes from allele : each alternative form that can take the same gene according to its sequence, which are located in the same place in the homologous chromosomes.
Codominance is a situation that occurs when two alleles different are found in the genotype and both are expressed. In this state, the expression of both alleles results in a phenotype (the manifestation of the genotype that varies according to the environment) with characteristics of both.
Therefore, it can be established that codominance is a type of genetic inheritance that has the characteristic that dominant characteristics of the two parents are inherited.
A clear example to understand codominance is that which establishes that an individual, in relation to his blood group, which has an A allele and an B allele will have a blood type AB. Of course, because the aforementioned alleles are codominant to each other.
With codominance, therefore, the expression of a gen in a heterozygous organism it is equivalent to that of its pair. Heterozygotes, in this way, present the two alleles of the same gene in relation to a certain character. In the incomplete dominance On the other hand, the two alleles are also expressed but in a genotype that has intermediate characteristics.
It can be said that, in heterozygous, there are two alleles that are expressed but that do not bind . Suppose a cross-coding with two species Horse: one black and one brown. The result of the cross will be a horse with black and brown spots since the two codominant alleles are expressed simultaneously.
Similarly, a flower TO yellow and a flower B of blue hue, in a cross-linking with codominance, will allow the creation of a flower AB whose colour it will be yellow with blue spots: both codominant characters are expressed.
In addition to all of the above, it is important to know that codominance is considered as such a discovery, a theory, established by the biologist and writer Teresa Audesirk (1950). apparently he raised the same forcefully in his work entitled "The life of the Earth", thus taking a great step in the field of biology that has allowed a lot of progress in the same during recent years. However, it is considered that he has not had the recognition he deserved.