At mutations can be defined as changes that occur in the genetic material. (DNA) of living organisms. These changes constitute an important source of genetic variability, being often responsible for the emergence of new species.
Changes in genetic material are extremely important, as it is the DNA that carries the information necessary for the protein synthesis. Some modifications in genes directly affect the protein to be synthesized, resulting in the appearance of an unexpected characteristic. It is worth noting that the mutations in the DNA can cause anything from physical changes to behavioral changes.
→ What causes mutations?
Mutations can occur because of errors in replication or external factors. In incorrect replication, at the time of synthesis of the new DNA molecule, errors can occur that make the copy not identical to the original. In addition to replication failures, we can mention the action of external agents, which can cause DNA breakage and incorrect repair. As an example of external factors, we can mention the radiation.
There are different types of mutations. There are those caused by replacement from one base to another, those in which it occurs inversion of new bases and also those in which the loss of a piece of DNA.
→ Do mutations occur at random?
Mutations occur randomly, that is, they do not appear as a way to meet an organism's need or even to harm it in some way. As they occur by chance, mutations generate different responses in the organism, affecting positively, negatively or not causing any change.
we call silent mutations those that cause changes in the genetic material, but the altered bases do not influence the proteins that will be produced. This is because the same amino acid can be encoded by different cracks, a property of genetic code what we call redundancy.
→ Is mutation always responsible for causing evolution?
Mutations are not always of evolutionary interest. Some mutations affect somatic cells and cannot, therefore, be transmitted to offspring. The only mutations important to the evolutionary process are those that affect reproductive cells, as these can be passed on from generation to generation, causing significant changes throughout the time. These mutations are called germinatives.
→ What are chromosomal mutations?
Chromosomal mutations occur in the structure of chromosomes or in the number of these structures in a cell. This type of mutation usually causes changes in more than one type of gene. As an example of chromosomal mutation, we can mention the Down's syndrome, which causes an increase in an individual's total chromosome number. The individual with Down syndrome has 47 chromosomes (and not 46, like most individuals), since he has three 21 chromosomes.
By Ma. Vanessa dos Santos
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/biologia/o-que-e-mutacao.htm
