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 genetical and cytological methods of locating inversion break points. Cytological Location: Cytological analysis is an important method of the physical location of the break points of inversion. (a) In plants like maize, and other organisms where pachytene analysis is easy, the breakpoints can be located by measuring the position of the inversion [...]
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 [...]