CHROMATIN
DNA in a nucleus is usually together with proteins. Such kind of DNA-protein complex is called chromatin. Continuous chromatin strands packed up in a certain way form a chromosome.
There is the same number of chromosomes in all cells of any organism, with only one considerable exception. Diploid cells (containing two copies of each chromosome) and haploid cells (containing one copy of each chromosome) are distinguished. Chromosome exists as continuous strand of chromatin packed up in a certain way. Chromatin is the name for DNA-protein complexes.
Each chromosome occupies in a nucleus its own space (Chubb, Bickmore, 2003). In nuclei of many vertebrates chromosomes with low gene density are stored at the periphery, and chromosomes with high gene density are in the very middle. (Parada, Misteli, 2002). Inactive X-chromosomes of females of vertebrates are also placed at the periphery of the intranuclear space. In yeasts silent regions of chromosomes are also forced to the periphery.
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Supplementary information
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