What is the role of the nucleus in a cell?

The nucleus serves as the control center of the cell, playing a crucial role in storing and protecting the cell's genetic material, specifically the DNA. This DNA holds the instructions necessary for growth, development, and the functioning of the organism. Furthermore, the nucleus is integral in coordinating various cellular activities, including the regulation of gene expression and the timing of cell division. By managing these processes, the nucleus ensures that the cell functions properly and responds appropriately to changes in its environment.

In contrast, generating energy for the cell is primarily the role of mitochondria, while ribosomes, responsible for protein synthesis, can be found in the cytoplasm and on the rough endoplasmic reticulum, not within the nucleus itself. Additionally, the nucleus does not facilitate cell movement, which involves structures such as the cytoskeleton and muscle fibers. Thus, the nucleus's primary function of housing genetic material and coordinating cellular activities makes it a vital organelle in the life of a cell.