We are comparing and contrasting the terms chromatin, chromatid, and chromosome. A chromosome is a collection of genes in the form of DNA found in the nucleus of cells. These genes are the basic material of heredity when the cell reproduces. Human cells have 23 pairs of chromosomes. Chromatin is a complex of DNA strands and proteins that are found in the nucleus. Associating and forming chromatin complexes with these proteins allows the DNA to more efficiently pack into the nucleus and also protects the DNA from damage. Finally, a chromatid is one half of a fully replicated chromosome set before they separate as a part of cell division. The two identical chromatid halves are held together by the centromere.