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:- 1. Classification of Haploids 2. Origin of Haploids 3. Meiosis. Classification of Haploids: According to their cytological features, haploids have been classified into different types (Fig. 17.1), a brief description of which is given below. I. Euhaploid: The chromosome number of such a haploid is an exact multiple of one of the basic [...]
The following points highlight the five main types of trisomics which is a cell tissue or individual possessing the extra chromosome. The types are: 1. Primary Trisomics 2. Secondary Trisomics 3. Telocentric or Telosomic or Telotrisomics 4. Tertiary Trisomics 5. Compensating Trisomics. Type # 1. Primary Trisomic: In this type of trisomic, the extra chromosome is normal and completely homologous [...]