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 aneuploidy in animals. Aneuploidy of sex chromosomes and autosomes have been reported in several animals. Nondisjunction is major source of aneuploid gametes Sturtevant reported that trisomic for chromosome 4 (triplo-IV) in Drosophila melanogaster ABCDEFGH was fertile in the female sex. In mouse, trisomics were found to be sterile or semi-sterile, but their [...]
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 [...]