Phenotype is an important concept adopted in Genetic and it is usually defined as the set of observable characteristics of an organism. In this sense, the morphological and physiological characteristics of an individual are included in this set.
→ What determines the phenotype?
As stated earlier, the phenotype is nothing more than the totality of observable characteristics of an individual, which are determined by the set of our genes.. Therefore, we can say that the phenotype is the expression of the genotype. However, it is important to emphasize that the phenotype is not only determined by the genes, it is also influenced by the environment in which an individual is inserted.
The relationship between genotype and phenotype is usually summarized as follows:
Genotype + Environment → Phenotype
An easy-to-understand example of phenotype is our skin color. Imagine that a person has fair skin, but after a few days at the beach, it becomes dark due to the production of melanin. The light skin color was genetically determined, however, its tone is influenced by the environment, in this case, by exposure to the sun on the beach.
We can see, therefore, that the phenotype is variable throughout the development of an individual and that the one presented at the current moment is dependent on the phenotype previously presented by the body. This is easily noticed when we observe a child and its changes over the years of life.
→ Is the entire phenotype easily observable?
Generally, when we say that the phenotype is an observable feature, we emphasize features such as skin, hair and eyes. However, the phenotype is not just the physical appearance of the organism. One example that creates confusion is blood type. When we say that someone has A, B, AB or O blood, we are referring to their phenotype which, despite not being easily observed, can be identified through laboratory techniques.
By Ma. Vanessa Sardinha dos Santos
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/biologia/o-que-e-fenotipo.htm
