Final answer:
The cell cycle, including stages like interphase, mitosis, and cytokinesis, helps Duncan grow from a calf to an adult elephant by enabling cell division and replication.
Step-by-step explanation:
The cell cycle is a series of stages that all cells go through during their life. In the case of Duncan growing from a calf to an adult elephant, cell division plays a crucial role. As Duncan grows, his cells will go through the cell cycle, which involves stages such as interphase, mitosis, and cytokinesis. During interphase, the cells grow and replicate their DNA. In mitosis, the replicated DNA is divided equally into two daughter cells. Finally, cytokinesis occurs, where the cytoplasm divides and two separate cells are formed. This cycle continues as Duncan keeps growing, allowing his body to consist of trillions of cells.