In this article we will discuss about:- 1. Introduction to Crossing Over of Genes 2. Factors Affecting Crossing Over of Genes 3. Cytological Basis of Crossing Over 4. Molecular Mechanism Crossing Over 5. Hybrid DNA Models of Crossing Over. Contents: Introduction to Crossing Over of Genes Factors Affecting Crossing Over of Genes Cytological Basis of Crossing Over of Genes Molecular [...]
The following points highlight the four theories proposed for the mechanism of crossing over. The theories are: 1. Janssen's Classical Theory 2. Belling's Copy Choice Theory 3. Uhl's Theory 4. Darlington's Theory of Crossing Over. Theory # 1. Janssen's Classical Theory: Janssen (1909) believed that prior to the formation of chiasmata the homologous maternal and paternal chromosomes come in pair [...]
The following points highlight the four main hypothesis proposed for the mechanism of crossing over. The hypothesis are: 1. The Classical and Neo-Classical Hypotheses 2. Partial Chiasma Type Theory 3. Belling's Hypothesis 4. Copy-Choice Hypothesis. Mechanism of Crossing Over: Hypothesis # 1. The Classical and Neo-Classical Hypotheses: The classical hypothesis of crossing over was proposed by Sax in 1932; it [...]