The period between two successive mitotic divisions is known as interphase. Although the cell may appear to be inactive during this time, during interphase the genetic material within the nucleus is being replicated. Cells at this point in the cell cycle have a prominent nucleus filled with chromatin, a granular-appearing material composed of a complex of protein and nucleic acid molecules. Within each nucleus, one or more nucleoli may be visible. You should also be able to identify the cytoplasm and cell wall.