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:- 1. Origin of Translocation 2. Types of Translocation 3. Effects. Origin of Translocation: Translocations can originate in the following different ways: (i) Translocations may originate spontaneously. (ii) They may be induced by mutagens, viz., ionizing radiations and many chemical mutagens, since they induce chromosome breakage. (iii) Translocations may be induced by growing plants [...]
In this article we will discuss about the interchanges involving more than two pairs of chromosomes. When 3 or more pairs of non-homologous chromosomes are involved in translocation, it is called a complex translocation, complex interchange or multiple translocation. In a single cell, two or more independent heterozygous interchanges show two or more quadruples at MI. Such interchanges are obtained [...]