Which of the following structures controls the activities of the living cell?

The structure that controls the activities of the living cell is the nucleus. The nucleus is a membrane-bound organelle found in eukaryotic cells that contains the cell's genetic material in the form of DNA. It acts as the control center of the cell, directing cellular activities such as growth, metabolism, and reproduction. The nucleus regulates gene expression, DNA replication, and cell division, and it also plays a role in the synthesis of RNA and proteins. The other organelles mentioned, such as the centrosome, chloroplast, Golgi body, and mitochondrion, have different functions in the cell and do not control the activities of the living cell.