BIOLOGY

THE CHROMOSOMES

In biology and cytogenetics, each chromosome is called a highly organized structure, consisting of DNA and proteins, which contains most of the genetic information of an individual.

In cell divisions that are mitosis and meiosis the chromosome presents its best known, well-delineated bodies in the form of  X, due to the high degree of compaction and duplication.

At the interface they can not be clearly visualized by the optical microscope because they occupy discrete chromosomal territories. In eukaryotic cells and archaea, unlike in bacteria, DNA will always be in the form of chromatin, ie strongly associated with proteins called histones and non-histones. The chromatin, organized on chromosomes, is found in the nucleus of eukaryotic cells and is visualized as a tangle of thin strands. When the process of duplication and division of the genetic material called karyokinesis begins, that tangle of strands begins a phenomenon of progressive condensation that allows to visualize each one of the chromosomes.