CUET Preparation Today
Assertion: Histones are basic in nature. |
Both Assertion (A) and reason (R) are correct and R is the correct explanation of A. Both Assertion (A) and reason (R) are correct but R is not the correct explanation of A. Assertion (A) is true but Reason (R) is not correct. Both Assertion (A) and Reason are false (F ). |
Assertion (A) is true but Reason (R) is not correct. |
The correct answer is Option (3) - Assertion (A) is true but Reason (R) is not correct. 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. |
