Final answer:
Eukaryotic cells spend the majority of their cell cycle in interphase, which is composed of the G1, S, and G2 phases, where the cell grows, replicates DNA, and prepares for division.
Step-by-step explanation:
Eukaryotic cells spend the majority of their cell cycle in interphase. This part of the cell cycle comprises three main phases: Growth Phase 1 (G1), Synthesis Phase (S), and Growth Phase 2 (G2). The cell engages in growth, performs routine metabolic processes, performs DNA replication, and prepares for cell division during interphase. This extensive duration allows the cell to execute its specific functions, such as those distinct to heart, kidney, or liver cells, as well as common ones that are essential for the everyday maintenance and preparation for subsequent mitosis and cytokinesis.
The Mitotic Phase, which comprises mitosis and cytokinesis, is a relatively brief period when the nucleus and cytoplasm divide, resulting in two daughter cells. However, in comparison, interphase is much longer and is the phase where cells spend most of their lifecycle.