Question

Choose the CORRECT statements about a nucleosome core particle

• A. It is a packaging unit of eukaryotic DNA
• B. It contains eight histones of four types
• C. It contains eight histones of five types
• D. Histones can be dissociated from nucleosome using high salt concentration

Hint:

The nucleosome core is composed of eight histones (H2A, H2B, H3, H4), and DNA wraps around this core to form the fundamental unit of chromatin in eukaryotic cells.

Answer 1

The Correct Option is A, B, D

Step 1: Understanding the nucleosome core particle.
A nucleosome core particle is the basic unit of DNA packaging in eukaryotes. It consists of DNA wrapped around a histone octamer. The histone octamer is composed of eight histone proteins from four different types: H2A, H2B, H3, and H4.

Step 2: Analyzing the options.
(A) It is a packaging unit of eukaryotic DNA: This is correct. The nucleosome is the fundamental unit of DNA packaging in eukaryotic cells.
(B) It contains eight histones of four types: Correct — The nucleosome core consists of eight histones, specifically two copies of H2A, H2B, H3, and H4.
(C) It contains eight histones of five types: This is incorrect. The nucleosome core contains histones from only four types, not five.
(D) Histones can be dissociated from nucleosome using high salt concentration: This is correct. Histones can be dissociated from the nucleosome by using high salt concentrations, which disrupt the ionic interactions between histones and DNA.

Step 3: Conclusion.
The correct answer is (B) It contains eight histones of four types, as the nucleosome core particle consists of two copies each of H2A, H2B, H3, and H4 histones.