The accommodation of the very long DNA strands that are part of a chromosome into the limited space of the nucleus is achieved b
y coiling the DNA around beads of histones into repeating subunits. These DNA-wrapped histones are called:_______. A. Solenoids
B. Nucleosomes
C. Chromatin loops
D. Rosettes
Chromatin is made up of certain repeating units called nucleosomes. Each nucleosome has a stretch of DNA that is wound around a complex of eight histone molecules. The eight histone molecules together make histone octamer. A DNA of 146 base pairs is wrapped around this scaffold made up of histone molecules.
A stretch of DNA called linker DNA joins the adjacent nucleosomes together. The DNA wound around the histone scaffold appears as a beadlike structure. One nucleosome scaffold has two copies of each of four different histone types. These are called H2A, H2B, H3, and H4. Histone H1 is joined to the linker DNA.
