In eukaryotic cells, the organelle that contains DNA is the nucleus. The nucleus serves as the control center of the cell, housing the cell’s genetic material in the form of chromatin, which is a complex of DNA and proteins. This organization allows for the efficient regulation of gene expression and replication. Inside the nucleus, the DNA is neatly packaged into chromosomes, which become visible during cell division.
Additionally, mitochondria and chloroplasts, found in animal and plant cells respectively, also contain their own DNA. However, the primary and most significant repository of DNA in eukaryotic cells is the nucleus, making it essential for cellular functions and heredity.