NEETZoologyMolecular Basis of Inheritance
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Histones are rich in acidic amino acid residues like glutamate and aspartate. Reason (R): In eukaryotes, negatively charged DNA is wrapped around a positively charged histone octamer to form a nucleosome. In the light of the above statements, choose the correct answer from the options given below:
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is incorrect
- D(A) is incorrect but (R) is correct
Correct answer
D. (A) is incorrect but (R) is correct
Step-by-step solution
Assertion (A) is incorrect. Histones are a set of positively charged, basic proteins. They acquire this charge due to the abundance of basic amino acid residues, specifically lysine and arginine, not acidic amino acids like glutamate and aspartate. Reason (R) is correct. In eukaryotes, DNA packaging involves the negatively charged DNA wrapping around the positively charged histone octamer to form a structure called a nucleosome. Therefore, Assertion (A) is incorrect but Reason (R) is correct. Answer: (A) is incorre