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 top eight types of Gene-Gene Interactions. The types are: 1. Interaction between Dominant Factors 2. Complementary Factors (9:7 Ratio) 3. Supplementary Factor (9; 3: 4 Ratio) 4. Epistasis(12:3:l Ratio) 5. Effect-of Inhibitory Factor (13: 3 Ratio) 6. Duplicate Factors (15: 1 Ratio) 7. Multiple Factors or Polygenic Inheritance 8. Lethal Factor (2:1 Ratio). Gene-Gene Interactions: [...]
In this article we will discuss about the characteristics and examples of Cytoplasmic Inheritance. Characteristics of Cytoplasmic Inheritance: Information concerning cytoplasmic inheritance is meagre but whatever is known about the occurrence and action that is highly confusing. Some of the cytoplasm characteristics appear to be under the ultimate control of chromosomes but in other cases there is no evidence of [...]