Question

Nucleosome is known as unit of packaging. Justify the statement with reasons.

Answer 1

• The negatively charged DNA is wrapped around the positively charged histone proteins arranged in the form of octamer to form a structure called nucleosome.
  
• A typical nucleosome contains approximately 200 bp of DNA helix.
  
• A nucleosome is the basic structural unit of DNA packaging in eukaryotes.
  
• Nucleosomes constitute the repeating unit of a structure present in the nucleus during interphase called chromatin, seen as thread-like stained (coloured) bodies.
• The nucleosomes in chromatin are seen as ‘beads-on-string’ structure when viewed under the electron microscope (EM).