The following points highlight the two main causes of ploids. The causes are: 1. Aneuploidy 2. Euploidy. Ploids: Cause # 1. Aneuploidy: The individuals carrying chrornosome numbers other than somatic or diploid (2n), which are not true multiples of basic chromosome number or genome are called heteroploids or aneuploids. Thus aneuploidy results due to an addition of loss of less [...]
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). [...]