NEET2026BiologyChapterActual
Which of the following features correctly describes the nucleosome present in eukaryotic chromatin?
Options
- AIt is formed by the wrapping of positively charged DNA around a negatively charged histone octamer.
- BThe core of the nucleosome is composed of two copies each of histones H1, H2A, H2B, and H3.
- CIt contains approximately 200 base pairs of DNA helix wrapped around a positively charged histone octamer.
- DThe histone proteins forming the octamer are rich in acidic amino acid residues such as lysine and arginine.
Correct answer
C. It contains approximately 200 base pairs of DNA helix wrapped around a positively charged histone octamer.
Step-by-step solution
In eukaryotes, DNA is negatively charged due to the presence of phosphate groups, while the histone octamer is positively charged because it is rich in basic amino acid residues such as lysine and arginine. The core of the nucleosome consists of two copies each of four types of histone proteins: H2A, H2B, H3, and H4. The H1 histone acts as a linker histone and is not part of the core octamer. A typical nucleosome contains approximately 200 base pairs of DNA helix wrapped around the positively charged histone octame