The following points highlight the three main types of allopolyploidy. The types are: 1. Segmental Allopolyploidy 2. Genome Allopolyploidy 3. Auto-Allopolyploidy. Type # 1. Segmental Allopolyploidy: Some degree of homology (partial homology) may exist between some chromosome of one genome and those of the other genome. Therefore, in such polyploids both bivalents and multivalents are formed. This type of chromosome [...]
In this article we will discuss about:- 1. Origin and Occurrence of Autotetraploids 2. Chromosome Pairing and Chiasma Formation in Autotetraploids 3. Fertility 4. Genetics. Origin and Occurrence of Autotetraploids: Autotetraploids originate both spontaneously and can be experimentally induced; the various means of their origin are briefly described below: A. Spontaneous origin: (1) In diploid (2x) plants, sometimes a tetraploid [...]
In this article we will discuss about:- 1. Meaning of Plasmids 2. Classes of Plasmid 3. Copies of Plasmids within a Cell 4. Phenotypic Effects of Plasmids 5. Origin of Plasmids and Viruses 6. Uses of Plasmids. Meaning of Plasmids: In bacterial cells, certain autonomously replicating circular genetic elements (DNA) are found some of which can become integrated into [...]