Final answer:
Chromatids are duplicated during the S phase of interphase, ensuring each daughter cell gets an exact copy of each chromosome. This is crucial for maintaining genetic integrity and preventing mutations.
Step-by-step explanation:
Chromatids are duplicated during the cell cycle's interphase, specifically in the S phase (synthesis phase). During this critical phase, each chromosome is replicated to produce two identical copies, known as sister chromatids. These sister chromatids are held together at the centromere by cohesin proteins, ensuring they remain attached until the right point in the cell cycle.
The importance of this process lies in ensuring that when a cell divides, each daughter cell receives an exact copy of each chromosome, maintaining the integrity of the genetic material. Errors during duplication or distribution of chromosomes can lead to mutations and other genetic abnormalities. Internal control mechanisms are in place to halt the cycle at checkpoints if issues are detected, ensuring the accuracy and fidelity of cell division.