Question

The net electric charge on $DNA$ and histones is

• A. both positive
• B. both negative
• C. negative and positive, respectively
• D. zero

Answer 1

Answer: (C)

negative and positive, respectively

Answer 2

$DNA$ is much more organised in eukaryotic chromatin and is associated with a variety of proteins most prominent of which are histones. Histones are rich in the basic amino acid residues lysines and arginines. Both the amino acid residues carry positive charges in their side chains. Histones are organised to form a unit of eight molecules called as histone octamer. The negatively charged $DNA$ is wrapped around the positively charged histone octamer to form a structure called nudeosome.