Chromatin and chromosomes. Genetic material
DNA can be in the form of chromatin or chromosomes depending on the cell phase.
DNA can be in the form of chromatin or chromosomes depending on the cell phase.
The chromatin is the way that presents the DNA in the cell nucleus. It is the basic substance of eukaryotic chromosomes, which corresponds to the association of DNA, RNA and proteins found in the interphase nucleus of eukaryotic cells and that constitutes the genome of these cells. Proteins are of two types: histones and non-histone proteins.
The basic units of chromatin are nucleosomes.
The interphase chromatin provides the genetic information for the transcription and translation processes. It distinguishes:
When the cell is about to divide (mitosis or meiosis), the chromatin condenses into bodies called chromosomes. Chromosomes, like chromatin, are made up of DNA associated with histones.
The number of chromosomes varies between species, but is constant in all cells of an individual.
The chromosome is a DNA molecule that contains genes, DNA segments that contain the information necessary to synthesize a protein or character of the individual.
A somatic chromosome is made up of:
All somatic cells of individuals of a species have chromosomes with the same shape. To distinguish it, we will look at the centromere, which will divide the chromosome into two arms (short or p arm and long or q arm) and on the constrictions of the chromatids.
According to the position of the centromere, chromosomes are classified into:
DNA, depending on the cell phase, can be found in the form of chromatin or chromosomes:
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