Chromatin is composed of a DNA and a protein. The DNA is a double helix in the cell nucleus packaged by histones, a special type of protein. Together they form the chromatin with a basic structural unit called nucleosome. The chromatin's functions are:
a. to package DNA into smaller volumes to fit in the cell.
b. to allow mitosis by reinforcing the DNA macromolecule
c. to prevent damaging of the DNA
d.to control gene expression and DNA replication