As the organelle that contains the genetic material of a cell, the nucleus can be described as the command center. As such, the nucleus consists of a number of structured elements that allow it to perform its functions. This section gives focus to the structure of the cell.

In general, the nucleus has a spherical shape as shown in most books. However, it may appear flattened, ellipsoidal or irregular depending on the type of cell. For instance, the nucleus of columnar epithelium cells appears more elongated compared to those of other cells. The shape of a nucleus, however, may also change as the cell matures.