The "control center" of the cell is the:

The nucleus is often referred to as the "control center" of the cell because it houses the cell's genetic material in the form of DNA, which contains the instructions necessary for the development, functioning, and reproduction of the organism. The nucleus regulates cellular activities by controlling gene expression and mediating the replication of DNA during the cell cycle. This central role in managing cellular processes aligns with its designation as the control center.

While the cytoplasm is the site of numerous cellular processes and the membrane sets boundaries and controls the movement of substances, neither performs the regulatory tasks attributed to the nucleus. The microtubular system, which is part of the cytoskeleton, provides structural support and is involved in intracellular transport, but it does not control cell activities in the way that the nucleus does. Thus, the nucleus' unique responsibility for overseeing and directing cellular functions justifies its role as the control center of the cell.