What are the regions of chromatin referred to as that are more densely packed and stains dark?

Step-by-step solution

The beads-on-string structure in chromatin is packaged to form chromatin fibers that are further coiled and condensed at the metaphase stage of cell division to form chromosomes. The packaging of chromatin at higher levels requires an additional set of proteins that collectively are referred to as Non-histone Chromosomal (NHC) proteins. In a typical nucleus, some regions of chromatin are loosely packed (and stains light) and are referred to as euchromatin. The chromatin that is more densely packed and stains dark a