Read the given passage and answer the questions that follow :-
In prokaryotes such as E. coli ,though they do not have a defined nucleus the DNA is not scattered throughout the cell. The DNA is held with some proteins in a specific region. in eukaryotes this organisation is much more complex .There is a set of positively charged basic proteins called histones. Histones are organised to form a unit of 8 molecules called histone octamer. The negatively charged DNA is wrapped around the positively charged histone octamer.

How many base pairs does a typical nucleosome of DNA helix contain?

200

The correct option is 2. 200 bp

The negatively charged DNA is wrapped around the positively charged histone octamer to form a structure called nucleosome. A typical nucleosome contains 200 bp of DNA helix.

Nucleosomes constitute the repeating unit of a structure in nucleus called chromatin, thread- like stained (coloured) bodies seen in nucleus. The nucleosomes in chromatin are seen as ‘beads-on-string’ structure when viewed under electron microscope (EM)