The nucleus is a membrane-bound organelle found in eukaryotic cells that contains the majority of the cell's genetic material. Within the nucleus, DNA is organized into multiple structures called chromosomes. Chromosomes are composed of DNA tightly coiled around proteins called histones, forming chromatin fibers. These fibers are then further condensed to form the visible chromosomes. The nucleus acts as a control center for cellular activities, including gene expression and DNA replication.
