Answer
When a eukaryotic cell is not undergoing mitosis, the DNA and its associated proteins appear as a visible network of dark fibers called the Chromatin.
Definition
Chromatin is a thread like structure that can be seen inside nucleus before cell division. It is a complex of DNA and histone proteins.
Forms of chromatin
Chromatin exist in two forms, that is
a. Euchromatin
It is less condensed and can be easily transcribed.
b. Heterochromatin
It is highly condensed and not transcribed as easy.
Organization of chromatin
Microscopy has shown the appearance of chromatin as beads on a string. The beads are called nucleosomes.
Nucleosome
Each nucleosome is composed of DNA wrapped around eight histone proteins. The nucleosome is then wrapped into a 30nm spiral called solenoid.