Control center of the cell.

• A. Chromatids
• B. Nucleus
• C. Centromere
• D. Golgi Apparatus

Answer: (B)

The control center of the cell is the nucleus. It contains the cell’s genetic material (DNA) and regulates what the cell does by controlling gene expression, essentially directing which proteins are made and when. The nucleus also houses the nucleolus, where components of ribosomes are assembled, and it’s surrounded by a nuclear envelope with pores that control the movement of materials between the nucleus and cytoplasm. The other structures have different roles: chromatids are the identical halves of a replicated chromosome that are separated during cell division; the centromere is the region that holds sister chromatids together; and the Golgi apparatus processes, sorts, and packages proteins and lipids for secretion or delivery elsewhere in the cell.