Which one of the following statements regarding histone proteins is correct?

Histones are a family of basic, positively charged proteins found in the nucleus of eukaryotic cells [4]. Their primary function is to provide structural support for chromosomes by associating with negatively charged DNA molecules [3]. In the nucleus, DNA wraps around an octamer of histone proteins (H2A, H2B, H3, and H4) to form repeating units called nucleosomes, which resemble beads on a string [3]. This association allows the extremely long strands of DNA to be compacted into a dense structure known as chromatin, fitting within the microscopic space of the nucleus [2]. While the cytoplasm contains various proteins, lipids, and carbohydrates, histones are specifically localized within the nucleus to facilitate DNA packaging and regulate gene expression [6]. They are not primary components of the mitochondrial membrane or associated with cytosolic lipids or carbohydrates [5].

Sources

1. [4] https://www.ncbi.nlm.nih.gov/books/NBK9863/
2. [1] https://www.genome.gov/genetics-glossary/histone
3. [3] https://www.ncbi.nlm.nih.gov/sites/books/NBK534207/
4. [2] http://www.nature.com/scitable/topicpage/dna-packaging-nucleosomes-and-chromatin-310
5. [7] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 2: The Invisible Living World: Beyond Our Naked Eye > Activity 2.3: Let us investigate > p. 12
6. [6] https://www.sciencedirect.com/topics/medicine-and-dentistry/cell-dna
7. [5] https://www.sciencedirect.com/topics/neuroscience/mitochondrial-membrane