Question

The given figure shows the structure of nucleosomes with their parts labelled as A, B and C. Identify A, B and C.

• A. A – DNA; B – H1 histone; C – Histone octamer
• B. A – H1 histone; B – DNA; C – Histone octamer
• C. A – Histone octamer; B – RNA; C – H1 histone
• D. A – RNA; B – H1 histone; C – Histone octamer

Answer 1

The correct option is A A – DNA; B – H1 histone; C – Histone octamer

Nucleosome is a structural unit of a eukaryotic chromosome which consists of a length of DNA coiled around a core of histones known as the histone octamer.

In the given figure of nucleosome structure, A represents negatively charged DNA which is wrapped around the positively charged core of the nucleosome known as the histone octamer (represented by C) . B represents H1 histone which is also known as ‘linker histone’. It plays a very important role in the compaction of chromosomes.