Which two structures are both duplicated during the S phase of interphase?

1. S stands for synthesis, and DNA replication happens here. 2. Replication turns each chromosome into a pair of sister chromatids. 3. The centrosome is copied during the same phase. 4. The two centrosomes later organize the mitotic spindle that moves the chromosomes. 5. The nucleus itself is not duplicated in S phase; it breaks down during mitosis instead. _Source: OpenStax Biology 1e (CC BY 4.0), Chs 10 and 11, section 10.2 The Cell Cycle_