How many histone proteins are included in a nucleosome?

A nucleosome, the fundamental unit of DNA packaging in eukaryotic cells, consists of a core of eight histone proteins. This octamer is made up of two copies each of four different histone types: H2A, H2B, H3, and H4. The DNA wraps around this octamer approximately two times, which helps in organizing and compacting the DNA into a more condensed structure, allowing it to fit within the cell nucleus. This structure is crucial for regulating gene expression and maintaining the stability of the genetic material during cell division. The correct answer emphasizes the significance of the octameric structure in the formation of nucleosomes, which is fundamental for understanding chromatin architecture and function in genetics.