In this article we will discuss about:- 1. Types of Chromosome Pairing 2. Factors Affecting Chromosome Pairing 3. Significance 4. Molecular Basis. Types of Chromosome Pairing: Chromosome pairing may be divided into three main types, viz., primary pairing, secondary association and non-homologous association, which may be further classified (Fig. 11.1). Primary Pairing: Primary pairing is observed at interphase, mitosis [...]
The following points highlight the fourteen main factors affecting crossing over and chiasma formation. The factors are: 1. Temperature 2. Age 3. Water Content 4. Sex 5. Nutritional Effects 6. Chemicals 7. Radiations 8. Shift in Population 9. Variation within the Organism 10. Chromosome Structure 11. Interference 12. Heterochromatin 13. Centromere 14. Genetic Effects. Crossing Over and Chiasma Formation: Factor [...]
The following points highlight the two main ways of representing chromosome set of species. The ways are: 1. Karyogram 2. Idiogram or Idiotype. Representing Chromosome: Way # 1. Karyogram: Photomicrographs of the chromosomes of a single representative somatic metaphase cell are clipped out and arranged in homologous pairs according to their size. If the chromosomes are small and there is [...]