Final answer:
During the S phase of interphase, DNA replication occurs resulting in sister chromatids for each chromosome, and the centrosome is duplicated. This phase ensures that daughter cells receive an exact copy of DNA and includes a checkpoint mechanism for DNA replication accuracy.
Step-by-step explanation:
During the S phase, or Synthesis phase of interphase, the cell undergoes critical processes to ensure that each daughter cell receives an identical copy of DNA for cell division. DNA replication is the primary event, where the cell's entire DNA content is duplicated. Each chromosome produces two identical sister chromatids, which are connected at a region called the centromere. Additionally, the centrosome is duplicated and will later facilitate the assembly of the mitotic spindle, necessary for segregating chromosomes during mitosis.
Moreover, the S phase includes a DNA Synthesis Checkpoint to verify the correct replication of DNA. Once DNA replication is confirmed, the cell can progress to mitosis (M). It is critical that DNA replication occurs faultlessly to maintain genomic integrity and prevent malfunctions like improper cell division or the development of tumors. The intricate process follows base pairing rules pivotal to the construction of identical DNA molecules.