Which structure acts as the control center of the cell?

The nucleus acts as the control center of the cell because it contains the genetic material (DNA) that holds the instructions for the cell's functions and activities. It is responsible for regulating cell growth, metabolism, and reproduction by controlling gene expression and the production of proteins. The nucleus ensures that the cell operates correctly by coordinating when genes are turned on or off in response to the cell's needs and external signals. This central role makes the nucleus vital for maintaining the life processes of the cell and, by extension, the organism as a whole.

Other organelles like mitochondria, ribosomes, and the Golgi apparatus have their specific functions—mitochondria produce energy, ribosomes synthesize proteins, and the Golgi apparatus modifies and packages proteins—but none of these structures manage the overall activities and genetic information of the cell like the nucleus does.