Grammatical agreement is linked to formal congruence: we say "La casa grande" and not "El casa grande" or "Las casa grande", for example.
Agreement is called agreement , consent or correspondence that exists between two elements . The term, which comes from the Latin concordantia , can be used in various contexts.
In the field of grammar , agreement is the formal congruence that must be registered between the inflectional information of those words that are linked at a syntactic level.
What grammatical agreement does is establish the grammatical relationship between the different constituents. For this, it appeals to cross references that lead each word to adopt a certain form according to the features determined by another word: both, due to these features, agree.
How grammatical agreement develops
Number and gender are two of the features that allow the development of grammatical agreement, which can be verbal, nominal or of another kind. To express oneself correctly, there must be an agreement between the articles, adjectives and nouns that make up a sentence, for example.
This means that, if we are going to use the noun “house” , for example, we will also have to use a feminine and singular article ( “the” ) and an adjective that is concordant (like “big” ): “The big house” . Expressions like “El casa grande” , “Las casa grande” or “La casa grandes” have no agreement.
In music , meanwhile, concordance is the proportion maintained by the various voices that, in a composition, sound together.
Genetic concordance implies the existence of the same phenotypic trait in two individuals.
The notion in genetics
We speak of genetic concordance , on the other hand, to refer to the existence of the same phenotypic trait in a pair of individuals, usually monozygotic twins, although it can also be any pair and individuals found in the group that is being studied.
The term phenotype is used in the field of genetics, but also in other areas of study of biology, to refer to the expression of the genotype (the genetic information in the form of DNA of a given organism), taking into account an environment. certain. Phenotypic traits can be seen both in the body and in the behavior of individuals; Furthermore, the characteristics studied are not always visible, something that can be exemplified with enzymes.
In other words, genetic concordance can be defined as the probability that the two members of a given couple have the same characteristic, or that one of them has a characteristic that has been observed in the other.
Study of the genetic concordance of phenotypic traits
Studies focused on monozygotic twin brothers seek to find the rate of genetic concordance of phenotypic traits, generally diseases, to know what percentage of these appear due to the environment and how much comes from the genetic load. Since the DNA of monozygotic twins is identical, they are expected to suffer from the same genetic diseases; Although this is true for monogenic ones, it is not true for polygenic ones.
Some twin studies have aroused controversial reactions, such as those that sought genetic concordance with respect to the intelligence or homosexuality of individuals.
When part of the study consists of modifying the position of the DNA directly, altering a simple nitrogenous base, the agreement is understood as the percentage of identical bases. In theory, this should be 100% in two samples from the same person or from monozygotic twins, but it is usually around 99% due to certain somatic mutations (changes in a nucleotide or in the organization of DNA) and test artifacts.
That said, it is understood that genetic concordance can also serve as a method for rating the accuracy of various tests. Using this procedure, it is expected that between parents and children there will be a concordance close to 50%, since each individual inherits half of the DNA of each parent.