|MadSci Network: Genetics|
I am not sure how much you know about Cell division. The genetic material in a non dividing cell, is contained present in the nucleus as a network of filaments called the Chromonemata. As soon as Cell division begins, the Chromonmata network condenses to form rod like structures called Chromosomes. Each Chromosome is made up of a pair of Chromatids and there is point at which these Chromatids join called the Centromere. The Centromere contains a structure called the Kinetochore. The Kinetochore functions as an attachment site for spindle fibres- These Spindle Fibres will then pull the Chromatids to opposite ends of the cell before the cell divides. Thus clearly the Centromere and the Kinetochore have an important role to play in Chromosome segregation during cell division. What I have outlined above is what is referred to as Mitosis. The Centromere and the Kinetochore also have an important part to play in the segragation of Chromosomes during Meiosis, the process of Gamete formation. If you were to look at a Chromosome down the microscope, you would see the Centromere as an indentation in the structure of the Chromosome. This indentation is always located in the same position in different types of Chromosomes making it a useful feature for identifying Chromosomes in Cytogenetics labs. You can find out more information on the Centromere as well as Mitosis and Meiosis on the Britannica Web Site on http://search.britannica.com/search? query=Chromosome or alternatively if you look at Molecular Biology of the Cell (Albert et al) you will find further information
Try the links in the MadSci Library for more information on Genetics.