How are the following formed and involved in DNA packaging in a nucleus of a cell?
(i) Histone octomer
(ii) Nucleosome
(iii) chromatin

Explanation

(i) Histone octamer : Histones are positively charged basic proteins Histones are rich in basic amino acids lysine and orginine both of which carry positive charge in their side chains , the Histone proteins are arranged to form a unit of eight molecules called the histone octamer.
(ii) Nucleosome : the negatively charged DNA molecule is wrapped around a positively charged histone octamer to form a nuclesome A usual nuclesome contains 200 bp of DNA holix.
(iii) chromatin : Nucleosome consitutes the repeating unit found in the necledelous called chromatin , chromation appers as thread- like stained bodies bodies and nucleosomes in chromatin appea as a bead -on- string structure when viewed under the electroin microsccopre.