NEETZoologyMolecular Basis of Inheritance
Which of the following statements is correct regarding the packaging of DNA helix in eukaryotes?
Options
- AHistones are organised to form a unit of eight molecules which are rich in acidic amino acid residues.
- BHistones acquire their charge depending upon the abundance of amino acids with negatively charged side chains.
- CA typical nucleosome contains 400 base pairs of DNA helix wrapped around the core.
- DThe negatively charged DNA is wrapped around the positively charged histone octamer to form a nucleosome.
Correct answer
D. The negatively charged DNA is wrapped around the positively charged histone octamer to form a nucleosome.
Step-by-step solution
In eukaryotes, the negatively charged DNA is wrapped around the positively charged histone octamer to form a structure called a nucleosome. This makes the fourth statement correct. The first statement is incorrect because histones are rich in basic amino acid residues (lysine and arginine), not acidic ones. The second statement is incorrect because the basic amino acid residues in histones carry positive charges in their side chains, giving histones their overall positive charge. The third statement is incorrect be