Practicing Success

Target Exam

CUET

Subject

Biology

Chapter

Molecular Basis of Inheritance

Question:

Nucleosome is associated with__________ molecules of histones.

Options:

Four

Nine

Two

Eight

Correct Answer:

Eight

Explanation:

The correct answer is Option (4) - Eight

In eukaryotes, there is a set of positively charged, basic proteins called histones. A protein acquires charge depending upon the abundance of amino acids residues with charged side chains. Histones are rich in the basic amino acid residues lysine and arginine. Both the amino acid residues carry positive charges in their side chains. Histones are organised to form a unit of eight molecules called histone octamer.

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.