Which of the following statements are incorrect?

P. Histones are rich in the acidic amino acid residues. Q. A typical nucleosome contains 200 bp of DNA helix. R. The chromatin that is more densely packed and stains dark is called as euchromatin. S. Euchromatin is transcriptionally active chromatin.

This option is correct because in eukaryotes, there is a set of positively charged, basic proteins called histones. Histones are rich in the basic amino acid residues, lysines and arginines, and in a typical nucleus, some region of chromatin is loosely packed (and stains light) and is referred to as euchromatin. The chromatin that is more densely packed and stains dark is called as heterochromatin.