[Campbell Biology P.379] Which statement accurately describes the composition and role of a ... | Practice Question
Which statement accurately describes the composition and role of a nucleosome in chromatin structure?
A: A nucleosome is a protein-free segment of DNA, 2 nm in diameter, representing the primary level of DNA packaging.
B: A nucleosome consists of DNA wound once around a core of four histone proteins, primarily involved in DNA replication.
C: A nucleosome is the basic unit of DNA packing, composed of DNA wound twice around a core of eight histones, playing a crucial role in regulating gene expression.
D: A nucleosome is a 30-nm fiber that forms during mitosis, consisting of DNA supercoiled around non-histone proteins.
Explanation
A nucleosome is correctly identified as the basic unit of DNA packing. It consists of DNA wound twice around a protein core made up of eight histone proteins two each of the four main histone types , and it's fundamental to chromatin structure and gene expression regulation.