The Different Characteristics of the Specie

Sometimes errors can occur in the transmission of genetic material from parents to offspring or in the structure of the genetic material causing serious disorders in human beings. Structural chromosomal abnormalities arise when different enzymes are not able to repair several breaks in the pattern of chromosomes or even if they are able to do so these repairs are not specific enough to avoid the abnormality. These can be caused by chemicals, radiation, viruses, or any other type of abnormal event. These structural abnormalities are classified into four main classes respectively. These are Deletions, Translocations, Inversions and Ring Chromosome (Langman &amp. Sadler 2006. Robbins et al 2005).
Other names of deletion are gene deletion and deficiency mutation. Deletion is the type of genetic abnormality in which a sequence of DNA is absent in the chromosome or a part of a chromosome is absent. It results in the loss of the genetic material from the chromosome. Translocation is also genetic aberration which occurs due to the rearrangement of the different parts of chromosome with nonhomologous chromosomes. Translocations are of two types that are reciprocal translocations and Robertsonian translocations. Reciprocal translocation is the translocation of genetic material between nonhomologous chromosomes. These type of chromosomal translocations are harmless. When the two acrocentric chromosome fuse near the centromere resulting in loss of the short arm, this type of translocation is called Robertsonian translocation. In Robertsonian translocation, the resulting karyotype in humans is 45 chromosomes. Inversion is the type of chromosomal abnormality in which a part of a chromosome is split and introduced back to the same chromosome. Inversion is basically the aberration in a single chromosome itself and is not associated with other homologous or nonhomologous chromosomes. Inversions are of two types paracentric and pericentric.&nbsp.Inversions that do not involve centromere are called paracentric inversions. Pericentric inversions are of that type&nbsp. which incorporates the centromere