Chromatin is the long thread-like structure that produces a chromosome that has DNA, RNA, and protein. Chromatin condenses to form a chromosome within the nucleus of eukaryotic cells and makes it visible. Chromatin is a lower order of DNA structure and chromosomes are a higher order of DNA structure. The main proteins in chromatin are histone proteins located at the middle of a nucleosome core particle. The function of histone proteins is DNA packaging. The DNA wraps around the eight histone proteins. A histone is the eight protein complex.

Karyogram is an image of homologous pairs of chromosomes from a cell, organized according to their size from largest to smallest for easy visualization. It is also known as an ideogram. A karyogram provides a geneticist to define a karyotype of a person.