The nucleus is a porous structure that houses the genetic material of the cell. The genetic material is made from a long polymer known as deoxyribose nucleic acid (DNA).

The DNA polymer is coiled into structures called chromosomes during cell division. Relatively small segments of DNA along the entire polymer are called genes and code for specific proteins.

The DNA molecule is tightly packed and coiled around special proteins called histones. Histones play a part in gene expression. DNA is not always tightly coiled and packed to form the visible chromosomes seen during cell division. All other times, the long DNA molecule and special proteins combine to form chromatin which exists as a loosely coiled structure..


View the video on the right for a better perspective of DNA in the nucleus of a eukaryotic cell.
DNA coils to form chromosomes in the nucleus but protein synthesis occurs with the ribosomes in the cytoplasm. How do the instructions go form the nucleus to the ribosome in the cytoplasm? Messenger RNA. Click to see an analogy.
Continue with RNA