A cleavage is a brokenness or one separation that is generated by a discrepancy, a divergence, a trauma or some other type of conflict. Depending on the context, this term from the Latin word scissio has different meanings.
When a society it breaks and its members distance themselves, a split occurs. Suppose that three people associate to start a company and, some years later, one of them decides to continue on their own. In this way, there is a split of the company and a new venture emerges as a detachment from it.
The Union of Soviet Socialist Republics (USSR ), on the other hand, was a State that existed for almost seven decades, merging several republics. In 1991 , with the splitting of the agreement, new independent nations emerged, such as Ukraine and Lithuania , among other.
In the field of medicine, excision is called the removal or ablation of an organ or tissue. Usually these excisions are performed by surgical intervention or through the application of chemical or physical means.
Excision is also the name that receives a asexual animal division form . Through this process, an individual is fragmented into two or more units, each capable of rebuilding and developing as a whole new organism. The sea stars , to name a case, are animals which can be reproduced by a process of excision.
Although from the point of view of our species it may seem impossible, there are several species of living beings capable of reproducing asexually, a phenomenon that begins with one or more cells and that goes through miotic processes (in equal parts cell division of the characteristic DNA) until the emergence of a new individual identical to its "parent" in genetic terms.
The star Sea is one of the most popular aquatic animals, and that makes it ideal as a reference to address the issue of excision. His body is flattened and has a minimum of five arms. It belongs to the class Asteroid (which is why it is also known as asteroid) which is composed of an average of one thousand nine hundred species , distributed all over the world. It is worth mentioning that the starfish is also able to reproduce sexually.
The split is also known as fragmentation. This process of asexual reproduction begins once the division has been completed or before, and in this way it is possible to talk about architomy or paratomyrespectively. The architomy can be caused by force majeure, such as an accident that leaves the individual mutilated, while the paratomia is carried out voluntarily and spontaneously.
In addition to the starfish, other animals that perform the architomy are the ofiuras . They are also known as ophuroid, and it is a class with symmetry pentarradial (they have five identical parts around their mouth) and look very similar to the first.
In some cases, the architomy is done transversely, that is, perpendicular to the axis of the body; this can also be seen in the planarians and the earthworm, which can begin the regeneration of a new individual based on the division of their body in various pieces.
Among the examples of paratomia, it is worth mentioning that of marine polychaete worms, which are capable of altering the posterior parts of their body so that they become new individuals that remain attached to the first.
The beta cleavage Finally, it is a kind of cracking or chemical cracking (a process which leads to the breakdown of the molecules of a compound, generating simpler elements).