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 [...]
In this article we will discuss about the interchanges involving more than two pairs of chromosomes. When 3 or more pairs of non-homologous chromosomes are involved in translocation, it is called a complex translocation, complex interchange or multiple translocation. In a single cell, two or more independent heterozygous interchanges show two or more quadruples at MI. Such interchanges are obtained [...]
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 [...]