Nuclear DNA

The majority of the cell DNA is in the nucleus. Long DNA particles are organized in separated structures - chromosomes, man has 46 of them. The number of chromosomes is species characteristic. Depending on the phase in which the cell is chromosomes reveal different state of condensation. The greatest is in metaphase, chromosomes became visible then as two sister chromatids. After the division (before the next one) chromosomes became less compact and they are no longer visible. It is called chromatin then.