What is the primary function of the nucleus in eukaryotic cells?

The primary function of the nucleus in eukaryotic cells is to control cell activities and carry genetic information. The nucleus serves as the command center of the cell, housing the cell's DNA, which contains the genetic blueprint essential for cell growth, metabolism, reproduction, and response to environmental changes.

Within the nucleus, the DNA is organized into chromosomes and, during the process of transcription, is transcribed into messenger RNA (mRNA). This mRNA then moves to the cytoplasm where it guides protein synthesis, which links back to the control of cellular activities. By orchestrating the expression of genes, the nucleus plays a crucial role in determining how the cell functions, responds to its environment, and replicates itself during cell division.

Other options refer to essential cellular functions but do not accurately represent the primary role of the nucleus. For instance, energy production occurs primarily in organelles like mitochondria, protein synthesis is facilitated by ribosomes, and material transport is handled by the endoplasmic reticulum and Golgi apparatus. Each of these processes is important for cell function, but they do not define the nucleus's main role as the genetic and regulatory hub.