The following point highlight the five main types of structural variation in chromosomes. The types are: 1. Deletion or Deficiency 2. Duplications 3. Translocations 4. Inversions 5. B-Chromosomes. Type # 1. Deletion or Deficiency: A deficiency means deletion of a small portion of a chromosome resulting in loss of one or more genes. A deficiency originates from breakage occurring at [...]
In this article we will discuss about the inversions in natural populations which is caused when the genes in a section of a chromosome is reversed. Inversions occur spontaneously in a large number of plant and animal species. But the most extensive work has been done in Drosophila in which they have been detected in a rather high frequency. In [...]
In this article we will discuss about the inversions in humans which occurs when the genes in a section of a chromosome is reversed. Pericentric Inversion: There are a number of reports of pericentric inversions in human. Breaks occur in both, short (p) and long (q) arms of the chromosomes. The length of inverted segment can be precisely identified by [...]