The DNA of every eukaryotic cell is stored in one or more located in the . 2. Before a cell divides, it copies all of its chromosomes. While the two copies of a chromosome are attached they are called . 3. A duplicated chromosome remains tightly paired with its partner at a region called the . 4. DNA and protein together form a complex called . 5. Chromosomes contain most of the cell's which acts as the molecule of heredity.