Mutations

Now we present an article of mutations but to talk about mutations we first need to understand what is a mutation?

Mutations occur in the DNA that is the hereditary material that all beings living have, if there is a change in the genetic code that the DNA has, a mutation will occur that has consequences for the individual. In the DNA are the codes that will define how the organism will be in every aspect.

Mutations can be good, bad or neutral for the organism. Most mutations are random because they do not give the individual what he needs. Many experts say that mutations are related to the aging of cells.

Once clear that they are the mutations these can be divided into two large groups that are somatic mutations and germline mutations.

Somatic mutation: The somatic mutation is the one originated by mitosis, that is, reproduction in cells that make up tissues.

From the mutated cell, more clones like it are created by cell division. An example is cancer in which some genes called protooncogenes mutate and the cells begin an uncontrolled division, as they divide they come together forming a tumor.

Germline mutations: these types of mutations occur in gametes, but this mutation is hereditary. An individual can have mutations in their germ line and will only realize in their offspring, unlike the somatic mutation this type of mutations do not affect the organism that has the gametes but the baby that was fertilized.    

                                                         

MUTATION CLASIFICATION.

Mutations are classified into three groups that are gene or point, chromosomal and genomic.

Gene mutations are those that alter the nucleotide sequence of a single gene, that is because instead of one thymine nucleotide one cytosine goes; also by the loss of nucleotides and the insertion of these or that there are more pairs of complementary nucleotides.

Another type of mutations are the chromosomes: the structures of the chromosomes are modified but not their number. The change occurs in the nucleotide sequence in the DNA that is then transcribed in the messenger RNA, causing affected genes.

Mutations in genes are divided into two groups. the group where the order of genes is affected (inversions and translocations) and the group where affects the number of genes (duplications and deletions).

Investments: is that a chromosome fragment has rotated 180 ° so the genetic sequence is inverted. When the centromere is affected and there is a change in the shape of the chromosome it is called pericentric inversion but when none of this happens it is called a paracentric inversion.

Translocations: is the change of position of a fragment of the chromosome, there are two types of translocation that are the reciprocal in which fragments are exchanged and transposition where this does not happen.

Duplication: occurs when a chromosome fragment is repeated on the same or another chromosome.

Deletion: it is produced by the loss of a chromosomal fragment and also by the loss of the genes that do not contain it

The genomic mutation is the change of the normal number of chromosomes that should have the individual, is given by an unequal distribution in the meiosis of the formation of gametes. This type of mutation can be divided into two which are euploidias and aneuploidies.

Euploidias: consists of changing the number of complete sets of chromosomes with respect to the normal number of the species, if within the sets of chromosomes there is an increase in number, that is, they are tripods or tetraploids, it is called polyploid. If on the contrary there is a single game (n) it is called haploid or monoploidy.

Aneuploidia: are the mutations that affect only the number of chromosomes of a couple. Aneuploidy occurs due to lack or excess of chromosomes an example in humans is the Down´s syndrome.