During which phase of the cell cycle does DNA replication take place?

• A. Interphase
• B. Prophase
• C. Metaphase
• D. Cytokinesis

Answer: (A)

DNA replication happens during interphase, specifically in the S (synthesis) phase. In this stage, the cell duplicates its entire genome so each chromosome is copied into two sister chromatids that will be separated later in mitosis. This preparation ensures that, when division occurs, each daughter cell receives a complete set of genetic information. The other stages listed are parts of mitosis or its completion: prophase is when chromosomes condense, metaphase is when they line up at the cell’s center, and cytokinesis is the division of the cytoplasm. Since replication must occur before chromosomes condense and separate, the synthesis phase within interphase is where DNA duplication takes place.