Which part of the cell is known as its control center?

The nucleus is known as the control center of the cell because it houses the cell's genetic material, DNA, which contains the instructions necessary for the cell's growth, development, and functioning. The nucleus directs all cellular activities by regulating gene expression, informing the cell about which proteins to produce at any given time. This regulation is essential for maintaining homeostasis within the cell and coordinating responses to external stimuli.

In contrast, the cell surface membrane functions as a barrier that controls the movement of substances into and out of the cell, but it does not regulate internal cellular activities. The cytoplasm is the site of many metabolic reactions and contains various organelles, but it does not serve as the control center. The cell wall, found in plant cells and some other organisms, provides structural support and protection but does not play any role in controlling cellular activities.