Chromatin consists of a complex of DNA, RNA and proteins that is present in the cell nucleus of the eukaryotes, in the form of a long filament. Histones are the main proteins that make up chromatins.
Chromatin is usually divided into two categories according to your condition: euchromatin and heterochromatin.
Euchromatin: when the chromatin filaments are less condensed it means that it has active DNA, that is, the cell is able to "read" the content of this genetic material.
Heterochromatin: the filaments are condensed, tangled together in a tangle. In this case, the DNA is inactive, as the cells at that moment are not able to encode the condensed genetic material.
It is possible to differentiate euchromatin and heterochromatin in the laboratory through color. When a special colorant is applied, the areas that have a more intense color mean an accumulation of chromatin, ie, heterochromatin. The lighter the region, in turn, means where the chromatin is less condensed (euchromatin).
See also: meaning of DNA and RNA.
sex chromatin
Also known as Barr's corpuscle, consists of one of the X chromosomes present in female mammals, which is condensed (inactivated). In humans, for example, females have two X chromosomes, one of which is condensed.
Males are formed by an X chromosome and a Y chromosome and, in this case, they do not have sex chromatin - with the exception of people with Klinefelter Syndrome.
Chromatin and Chromosome
The difference lies in the fact that the chromatin filament is found in the nucleus of the interphase cell, that is, it is not dividing. From the moment the cell starts its process of division, the chromatin filaments curl in on themselves and condense. That's how chromosomes are born.
In short, chromatin and chromosome are almost the same thing, but with different structures.
Learn more about meaning of chromosomes.
