In this article we will discuss about the classification and origin of aneuploidy in chromosomes. Classification of Aneuploidy: Broadly, aneuploids may be divided into the following two classes (a) hypoploid and (b) hyperploid. In a hypoploid, the chromosome number is lower than the euploid number, whereas in a hyperploid it is greater than the euploid number. A detailed classification of [...]
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. 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 [...]