The significance of the cell cycle in cellular biology lies in its role in cell growth, division, and repair. It consists of stages such as interphase and mitosis, ensuring accurate DNA replication and distribution to daughter cells. The regulation of the cell cycle is critical for maintaining genetic stability and preventing cell abnormalities, which can lead to diseases like cancer. Understanding the cell cycle also aids in the development of treatments targeting cell division, making it essential for advancements in medical research.