The below mentioned article provides a note on nullisomy in chromomes. The cell, tissue or organism in which both the homologues of a chromosome are missing from the somatic chromosome complement is called nullisomic (2n-2), and the condition is called nullisomy. If two pairs of homologous chromosomes are absent, the cell, tissue or organism is known as double nullisomic (2n-2-2). [...]
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:- 1. Distribution and Occurrence of Polyploidy 2. Classification of Polyploidy. Distribution and Occurrence of Polyploidy: Polyploidy is wide spread in plant kingdom but is less common in animal kingdom. Darlington and Janaki-Ammal in 1945 and Stebbins in 950 estimated that polyploids make up 30 to 35% of Angiosperms. In certain families, very high [...]